His ship repaired, Linx prepares to take off as the Doctor races to stop history changing.
The Doctor isn’t harmed, and Linx is rendered immobile when Rubeish, acting on a hint from the Doctor, hits his probic vent (a Sontaran refueling point on the back of their necks which is also their main weakness). Rubeish and the Doctor use the osmic projector to send the scientists back to the twentieth century. Sarah now inveigles herself into Irongron’s kitchen, using the opportunity to drug the food, thereby knocking out Irongron’s men.
A recovered Linx now determines his ship is repaired enough to effect a departure. Once more he encounters the Doctor, and they wrestle in combat. A crazed and half drugged Irongron arrives and accuses Linx of betraying him; the Sontaran responds by killing him. As Linx enters his spherical vessel Hal arrives and shoots him in the probic vent, and the Sontaran warrior falls dead over his controls, triggering the launch mechanism. Knowing the place is about to explode when the shuttle takes off, the Doctor hurries the last of his allies out of the castle. It explodes moments before the Doctor and Sarah depart in the TARDIS.