The Doctor urges Peto and Grissell to build a mental barrier between themselves and their host. In the square, the lions chase after Nyssa and Tegan; they kill seven civilians and a policeman in the process. Finally, the Sevakrill are forced out and the lions return to their plinths. The Doctor spends two weeks lowering the missile into a tunnel beneath the column and builds a floor over it. He leaves behind a short range sensor that will warn him should the missile ever be activated. He comments passingly that he might check to see if someone has tampered with Cleopatra's Needle.
Tegan recalls the last time that the Doctor climbed something "really tall" and notes that it did not go well. This refers to the instance his predecessor climbed a Pharos Project Radio telescope, was tilted off the gantry by the Master, and fell to the ground, where he regnerated. (TV: Logopolis)