With the crystal of Kronos in his possession, the Master releases the Chronovore.
In Atlantis the crystal of Kronos is protected by a guardian who is half man, half beast.
The Master heads to Atlantis but he and the Doctor confront each other in the time vortex.
The Master uses TOMTIT to summon threats from the past to attack UNIT.
After a disastrous attempt to summon Kronos, the Master prepares to use TOMTIT once again.
The Master is using a device called TOMTIT to summon a creature from beyond time.