Romana summons Leela to deliver bad news: Andred has been found murdered in the Vaults. Leela takes the news stoically, but vows to find her ex-husband’s killer and avenge his death. Romana warns Leela not to overreact, for fear that Darkel will use her behaviour as further evidence that aliens should not be permitted on Gallifrey. The frustrated Leela lashes out, accusing her friend of being relieved that Andred is no longer around to cause trouble. Romana assures Leela that she grieves for her loss, but insists that, while her Presidency is under threat, they must be seen to act according to the law. In the meantime, she asks Leela to put her anger to good use by focussing her attention on her work as security advisor to the Academy. But then Narvin delivers word of the bombing, and as the horrified Romana and Leela set off to investigate, Romana orders K9-II to continue work on the secret project they were discussing earlier.

Darkel has already arrived at the ruins of the Academy, and is giving a statement to Antimon blaming the bombing on Gallifreyan insurrectionists who have resorted to violence in order to register their disapproval of Romana’s policies. Though Darkel claims to abhor their methods, she understands their motives, as Romana is allowing aliens to learn the deepest secrets of Time with no guarantee that they will use their knowledge responsibly. Romana and Leela arrive and are infuriated to see Darkel using the deaths of innocent students to advance her political agenda, and Leela nearly openly accuses Darkel of responsibility for the bombing herself. Darkel takes offence, insisting that she is acting entirely within the bounds of the law to restore order to Gallifrey and that Romana’s policies are responsible for this tragedy; however, Romana insists that Darkel’s policies will drag them back into a stagnant past. Darkel leaves, with Antimon close behind her, delighted to have footage of this debate.

Narvin is trying to co-ordinate the aftermath of the bombing, which has cost 20 lives so far. Many students are demanding vengeance, and Narvin has had to lock some of them up for their own protection, despite the risk that the Time Lords will be accused of holding political prisoners. Romana nearly succumbs to despair, seeing the carnage that has resulted from her policies and wondering whether they really are for the best; for her part, Leela blames herself for failing to protect her charges, especially when she sees that Galadina is one of the dead. Romana knows one way to stop this from happening again, but she’s unwilling to pay that price, and she thus orders Leela to take charge of the investigation into the bombing -- while Romana contacts the other temporal powers and tries to prevent them from launching an all-out attack on Gallifrey.

Elsewhere, Narvin confronts Darkel, accusing her of misusing the powers he’d given her and of somehow arranging the bombing; however, while she concedes that the incident has helped her cause, she insists that she was not responsible. Narvin agrees that the alien students pose a security risk to Gallifrey, which is why he gave Darkel access to secret CIA codes and resources to help her campaign against Romana -- but he also believes that Gillestes could never have gotten as far as she did unless she was being helped by a Time Lord sympathetic to the Free Time agenda. He now fears that any investigation into the bombing could turn up ties to the CIA and implicate him, but for the moment, he and Darkel have no choice but to continue working together. Narvin leaves to begin his investigation -- and Darkel heads down to the Vaults with Commander Maxil in order to consult with her political advisor...

Leela and K9-I intend to study footage from the Academy’s surveillance system, but K9 admits that he has yet to decipher some of the safeguards that Chancellor Braxiatel put in place -- which may be why he failed to detect the bomber bypassing security. The important question is: how did the culprit disguise the bomb so the security systems failed to recognise it as a threat? When K9 accesses the security footage, he finds that 20 microspans of footage has been deleted from the record. Leela then finds somebody trying to steal a fragment of electronic hardware from the evidence locker; she and K9 drive off the thief, but are unable to identify him or her. K9, unable to identify the fragment, suggests that Leela co-operate with Narvin in order to gain access to the CIA’s resources, and barter the electronic fragment in exchange for access to the rest of the evidence into the bombing. Leela reluctantly makes the attempt, and although Narvin is initially unwilling to bargain, he reluctantly concedes that the fragment might be significant if someone was desperate enough to try stealing it. When he remains wary of giving Leela access to the CIA’s resources, Leela threatens to tell Romana that Narvin is withholding evidence, and Narvin reluctantly agrees to let her view Antimon’s footage of the bombing -- on condition that he work alongside her.

Romana tries to convince the Nekkistani Ambassador to stand down from a war footing, insisting that she is doing all she can to protect his people. Nevertheless, she agrees to let the Nekkistani evacuate their citizens from Gallifrey, if this is what they wish. Before signing off, the ambassador warns Romana that they will respond in kind if any more of their people are killed. As the situation deteriorates, it seems that Romana must once again turn to Pandora for advice; however, K9-II warns Romana that Pandora is gaining greater control over the Matrix partition in which she has been confined. Nevertheless, she remains trapped within that partition, and the security measures already in place will enable K9 to access the partition and allow Pandora to communicate through him without setting her free. On Romana’s instructions, this is what K9 now does.

Before questioning Pandora, Romana warns her that K9 now has the ability to squeeze the data partition, constricting the data space within and causing Pandora the equivalent of pain. She then demands that Pandora help to avert the dark future she’s seen in her dreams. However, Pandora claims that this future is inevitable; Romana can only avert civil war by stepping down, and if she does so, Darkel will reverse all of Romana’s achievements. Romana accuses Pandora of helping Darkel in order to manipulate her into this position, and orders K9 to squeeze the partition. Under threat of torture, Pandora agrees to help Romana, but still insists that there is only one way for Romana to eliminate all opposition to her policies. Romana knows what this means -- but will her actions prevent civil war, or bring it about?

Despite Narvin’s scepticism, Leela spots something interesting in Antimon’s footage: Darkel was at the Academy before the bombing, which implies that she knew it was going to take place. Leela notes that Narvin does not dismiss this possibility out of hand, but he warns her that they’ll need positive proof before accusing Darkel of terrorism. Leela suspects Narvin of colluding with Darkel’s schemes, but he insists that, despite his personal reservations, he knows that killing the alien students would only provoke reprisals and place Gallifrey under threat. K9-I offers to scan the Academy’s sensor net for signs of tampering, and Narvin, conceding that K9 is a remarkably versatile computer, connects him to the CIA processors. K9 discovers that the bomber has placed a firewall in the Academy security net to hide the evidence of his tampering, but Narvin easily bypasses the firewall and finds the keystrokes used to delete the security footage. Unfortunately for him, the user who deleted the footage logged in as “narvin,” which seems to confirm Leela’s suspicions. Narvin insists that he’s being framed, and Leela reluctantly concedes that this is more likely than Narvin having logged on under his own name. Narvin then reveals that the alien students are being evacuated from Gallifrey for their own safety, and that his most trusted operatives are providing security -- but Leela reads between the lines and realises that Narvin is hoping to lure the bomber out into the open by using the innocent students as bait.

While Narvin analyses the damaged electronic component that the bomber tried to steal, K9 heads for the scapheport to scan for bombs, and Leela reports her progress to Romana. She finds Romana studying Andred’s body, wondering to herself what his motives were in the end -- and whether Leela trusts her any longer. Leela notes that it’s difficult for her to get in touch with Romana or K9-II these days, and asks whether Romana is preparing for battle, but Romana claims that she’s just dealing with matters of state. Leela reports her suspicions that Darkel has somehow gained access to the CIA’s resources, and Romana deduces that Narvin tried to help Darkel’s campaign only to see it backfire on him. She decides to visit the scapheport personally to ensure that the students are evacuated safely, but Leela tarries for a moment to address her dead husband. She is sorry for treating him so cruelly in his last days of life, and vows to avenge his murder -- and then take her own life so that they can be together again.

Narvin knows that even if he confesses to Romana that he supplied CIA resources to Darkel, he’ll still take the fall for it whether or not Darkel is responsible for passing on those security codes to the bomber. However, Darkel warns him not to change sides now; the heads of the Chapters will support her when she moves against Romana, and she’s almost ready to act. She suspects that Romana plans to stop her by declaring herself Imperiatrix, but Narvin is convinced that this would go against her ethics. Nevertheless, Darkel still needs to prove that Romana’s policies are responsible for the violence on Gallifrey before the High Council will move against her. Narvin is beginning to suspect that his own men are more loyal to Darkel than to him, but there’s little that he can do about that, other than ensure that his most trusted guards provide security at the scapheport. Although Darkel concedes that the bombings have benefited her politically, she still maintains that she’s not responsible, and that the violence is indeed due to fundamental flaws in Romana’s policies.

In the scapheport, Antimon reports on the aliens’ evacuation from Gallifrey, claiming that this proves that Romana’s policies are untenable and that Gallifrey can once again reclaim its vaunted position as overseer to the lesser temporal powers. K9-I then arrives to scan the scapheport, and to Antimon’s horror, he detects a bomb. The panic-stricken commentator removes the hard drive from his camera drone and flees to safety, and moments later, K9’s scan apparently triggers the bomb’s detonation sequence. K9 finds that he is unable to defuse the bomb, and warns the occupants of the scapheport to evacuate. Gallifreyans and non-Gallifreyans alike flee in a panic as Romana and Leela arrive, and the stampede prevents Leela from getting into the scapheport to rescue her K9. Commander Hallan orders his guards to shut the blast doors, and when Romana and Leela protest that he’s sealing people inside with the bomb, he orders his guards to restrain the women for their own safety. K9 is trapped on the other side when the shutters descend, as are many other innocent people -- and the bomb goes off, killing them all.

Enraged and grief-stricken, Leela stabs Hallan in the arm before his guards can overpower her. Romana furiously orders them both to restrain themselves, and angrily vows to bring up Hallan on charges for disobeying her instructions to keep the blast shutters open. Now, innocent people have died and Gallifrey may find itself at war. Romana orders the guards to open the shutters, and looks in despair at the ash and twisted metal beyond. Furious, she orders Hallan to raise the transduction barriers to protect Gallifrey from reprisals from the other temporal powers. As Hallan and the guards depart, Romana sinks into despair; her attempts to change Gallifrey for the better have led to violence and death, and it seems that the only way for her to lead Gallifrey into the future is by force. As Leela tries to console her friend, she finds the shattered remains of her K9; his warning saved many lives, but he’s lost his own. Leela has lost the Doctor, her husband, and now her most loyal friend -- but Romana insists that she still needs Leela’s help and friendship.

Narvin and Darkel arrive, and Romana angrily turns on them, threatening to use the evidence found by K9 to strip Narvin of his position and perhaps even have him vaporised. Darkel in turn accuses Romana of using Narvin as a convenient scapegoat, but Narvin’s only defence is that he suspects that the CIA is no longer under his control -- which hardly helps his position. Romana sends Narvin and Leela to analyse the mysterious metal fragment as Darkel wonders aloud whether this carnage represents Romana’s vision for Gallifrey’s future; furious, Romana warns Darkel not to use this horror for her own political gain. Darkel gives Romana one chance to give in to the inevitable and step down gracefully, but Romana refuses, insisting that her policies are the only way forward. As far as Darkel’s concerned, however, Romana is simply determined to hold onto power for its own sake. She thus demands that Romana call a council to discuss action against this threat, and Romana realises that she has no choice but to do so -- and that there is now only one way for her to defeat her political opponents.

Narvin’s operatives have identified the metal fragment as the hard drive from one of Antimon’s camera drones, which was all but destroyed by the explosion -- unsurprisingly, as the recovered footage seems to imply that the camera itself was the bomb. As Leela and Narvin watch the footage, Leela senses something strange, and then Narvin sees for himself that Antimon seems to be in two places at once. Presumably, he used a TARDIS to return to the scene a second time -- and he is the one who controls the cameras. When Narvin tries to read Antimon’s biodata extract, he finds that access to it has been restricted using Narvin’s own codes. Narvin tries to report his findings to Romana, but Commander Hallan refuses to connect him, claiming that Romana is attending an emergency High Council meeting -- which is to be broadcast live as part of Darkel’s political campaign. Hallan signs off before Narvin can warn him that the broadcast cameras could contain bombs, and Narvin rushes off to warn Romana in person while Leela tracks down Antimon.

The council is ready to convene, and Romana is preparing to pull a drastic ace out of her sleeve. Through K9-II, Pandora has located the Great Key of Rassilon, with which Romana will be able to take the final step to secure power on Gallifrey. Darkel suspects what Romana is planning to do, but is convinced that such a display will only prove that Romana has become dangerously unhinged by her desire for power... just as Darkel’s political advisor had informed her. Meanwhile, Leela locates one of Antimon’s camera drones and damages it, forcing it to return to its master for repairs -- and leading Leela right to him. Unfortunately, he sees her coming, and attacks her from behind when she bursts into his hiding place. He admits that he is indeed the bomber -- and knocks Leela out so she can’t stop him from detonating the cameras in the Panopticon and killing every Time Lord at the emergency council meeting...

Gold Usher opens the Council, and after trading initial unpleasantries with Darkel, Romana addresses the assembled heads of the Chapters. She insists that her policies are the only way forward for Gallifrey, but concedes that she has been unable to secure the planet’s safety against those who disagree with her. Therefore, she has concluded that this election is not over policy, but over control -- and to maintain control, she now declares herself Imperiatrix. However archaic, the law is still the law, and this act is perfectly legal. Romana has the Great Key, the Sash, the Road, and the Coronet of Rassilon, giving her total control of the secrets of the Time Lords; her personal guard will now become the Imperial Guard, and the Chapters will be dissolved, giving Romana ultimate executive power. Gallifrey has just become a dictatorship.

As Darkel denounces Romana’s last desperate attempt to hold onto power, Narvin forces his way past Hallan into the Panopticon and publicly accuses Darkel of being in league with the bomber. He tries to prove his claim by opening up one of Antimon’s cameras to reveal the bomb inside, but realises too late that he’s activated a booby trap; he manages to shout out a warning just in time, but the bomb practically explodes in his hands. Grievously, perhaps even mortally injured, he confesses to Romana that he supplied CIA security codes to Darkel in order to support her coup attempt. Romana orders Hallan to have Narvin taken to a medical station immediately, but while she’s occupied, Darkel addresses the gathered Time Lords, insisting that this incident proves that Romana is incapable of protecting them against external threats. She thus declares Romana unfit for office and orders Hallan and his guards to place Romana under arrest. The heads of the Chapters make no move to protest this, which is exactly what Romana had expected -- and planned for. She now reveals that her personal guards have infiltrated Darkel’s forces and outnumbered them. Darkel thought Hallan was on her side, but he can see who’s about to win here, and he orders his men to shoot down Darkel’s guards instead, thus bringing the coup attempt to an end.

Romana now orders Hallan to arrest Darkel and her supporters, but before he can do so, Antimon appears on the public video screen and reveals that he’s been manipulating them all. Darkel was indeed working with him, but was unaware of his true agenda. She thought he was just a reporter who would help her cause by broadcasting evidence of Romana’s failures of policy and swaying the High Council in her favour -- but in fact, he’s used her to gain access to the CIA. He is the one who supplied Gillestes with the dogma virus, and when she failed to spread it, he resorted to more drastic measures to get his point across. Antimon is a Free Time agent, and he’s been bombing non-Gallifreyans, even those sympathetic to his cause, just to show that Free Time is more committed to its cause than to any individual. Romana points out that she’s been trying to share Gallifrey’s secrets with those capable of understanding them, but Antimon scoffs, insisting that everyone should have access to time travel regardless of whether the Time Lords believe they can be trusted with it. He now claims that the assembled Time Lords are all infected with the dogma virus; when he detonates his cameras, those who survive and regenerate will be converted to his cause, and in the aftermath, those behind the Free Time movement will seize control of Gallifrey and ensure that time travel is open to all rather than the privileged domain of a few.

However, Leela has revived earlier than Antimon expected, and she now attacks and stabs him through both of his hearts to avenge those he has murdered. She accuses him of killing Andred when her husband turned against Darkel -- but Antimon claims that it was Romana who killed Andred, and that the proof is in his camera drones. Leela does not believe him, but is shaken for a moment, long enough for him to trigger the bombs’ countdown sequence before he dies. Romana orders K9 to transmit a pulse wave to deactivate the bombs, but K9 is still possessed by Pandora, and she refuses to release him until Romana puts on the Coronet. Romana fears that Pandora will try to manifest through her, but Pandora reminds her of the safeguards that will prevent her from doing so. With only microspans left before the bombs go off, Romana reluctantly dons the Coronet, and Pandora releases K9 and allows him to transmit the pulse wave, tricking the bombs into believing that they’ve already detonated and thus halting the countdown. But before Romana can take off the Coronet, Pandora breaks through the Matrix defences and triggers the Imperiatrix Imprimatur within Romana’s genes. Drawing biological matter out of a biodata imprint within the Matrix, Pandora emerges from Romana’s body like an ectoplasmic manifestation, and appears in the Panopticon -- in the form of Romana’s first incarnation.

Romana-1 now reveals that she’s been manipulating events all along. Even when Romana tried to rid herself of the Imprimatur by regenerating, her first personality’s memory and personality remained lurking in her subconscious, manipulating her second incarnation and growing ever stronger as this future became more and more probable. Romana-1 has been giving Darkel political advice in order to shape her into a serious threat to Romana-2’s Presidency and thus force Romana-2 into this position. And now that Romana-1 is alive once more, she claims the title of Imperiatrix taken by her second incarnation. Romana-2 realises that her prophetic dreams were generated by Romana-1’s presence within her mind, and that it was always Romana-1’s destiny to become Imperiatrix, not hers. However, by manifesting in corporeal form, Romana-1 has made herself vulnerable -- and since Darkel has now been revealed to be in league with the terrorist who threatened them all, Romana-2 has the authority to place her and her co-conspirators under arrest, including Romana-1. Hallan chooses to stand with the winning team and marches away the protesting Darkel. Leela arrives, and is startled to see Romana-1 being marched out of the Panopticon on Romana-2’s orders -- but as she goes, Romana-1 warns her second incarnation that she’ll be back, sooner than Romana-2 thinks.