Maxil has the wounded Doctor returned to the TARDIS, from which he removes the space-time element.
Robin meets Colin's cousin at the airport — Tegan. He attempts to explain what has happened.
Maxil brings the Doctor at gunpoint to the High Council. President Borusa presides over the debate. The Doctor demands an investigation into who leaked his biodata extract. But Borusa refuses to listen and decides the Doctor must be executed to stop the anti-matter creature.
Tegan goes to the authorities but they refuse to investigate Colin's disappearance. Tegan decides to investigate for herself.
Nyssa tries to plead the Doctor's case but the Time Lords are convinced billions will die unless they execute the Doctor. Councilor Heddin is the only one sympathetic to her view. Concerned over the possibility of treason, he pushes the Castellan to investigate. Damon also comes to Nyssa and explains about the transmitted biodata, which he has slipped to the Doctor.
The glowing creature, meanwhile is delighted by the pending execution. Assisted by Colin, he makes his preparations.
Heddin arranges for Nyssa and Damon to meet with the Doctor. He warns them that if a Councilor is cooperating with the creature, Gallifrey is in danger. He asks for a new time-space element to be placed in the TARDIS before Maxil takes him away again.
As Damon and Nyssa investigate, the Doctor is led to the execution room. Nyssa, losing patience, attempts to stop the execution by holding a staser on Borusa. But the Doctor persuades her to surrender.
He is placed into the chamber as the anti-matter creature activates his own machinery. A bright glow envelopes the Doctor, over which the image of the anti-matter creature appears. But the image vanishes, revealing the empty chamber. The sentence has been carried out…