Commander Lang. They take him back to the TARDIS where he reveals his whole squadron has been destroyed. Believing the Doctor to be responsible, he points his gun at the Doctor and threatens to kill him. Peri pleads with Lang, telling him that the Doctor had in fact saved him, but he faints away. The Doctor is not keen to treat Lang, more concerned for his own life, but eventually agrees to Peri's persuasion. Edgeworth argues with Romulus and Remus, making them do Mestor's work. He scolds them for setting up a distress signal, so they are not allowed to use electronic equipment to solve the equations they have been set. An image of Mestor appears and gives the twins a more blunt threat — work for him or have their minds destroyed. On the TARDIS scanner, the Doctor and Peri see a building — something which has no place on an uninhabited asteroid. Leaving Lang behind, they find a tunnel which may lead to the building, but on exploring find two aliens wielding guns. The Doctor cowers in fear and pleads with them to kill Peri instead of him. They are led off and are brought before Edgeworth. The Doctor claims to be a pilgrim to Titan 3, but Noma, one of the aliens, says they are spies and should be shot. The Doctor suddenly recognises Edgeworth as an old friend – Azmael, master of Jaconda, whom he last saw two incarnations ago. When the Doctor sees Romulus and Remus and discovers it is Azmael who has abducted them, he is disgusted. Azmael teleports away with the twins and the aliens, leaving the Doctor and Peri locked in the building. The Doctor starts to break the lock's combination, but Peri discovers Noma has set the base to self-destruct. The Doctor improvises a solution to teleport them back to the TARDIS. Peri makes a successful return, but weeps when the Doctor has not appeared when she sees the base explode on the scanner. A glimpse of the Doctor is seen appearing in the TARDIS; he was delayed returning because he was using Peri's watch to synchronise their arrival, but the watch had stopped. The Doctor is surprised at Peri's compassion when she thought he had died. On Jaconda, Mestor is seen putting one of the bird-like Jacondans to death for a petty offence. The TARDIS arrives, but instead of the