they fail to act as, in the future, they already have. Turlough is skeptical until he finds a note in the diary, confirming the Doctor's warning, and written in his own handwriting. The Doctor concedes that they should take Kamelion along, but Kamelion finds that the energy fields which keep the atmosphere bubble intact interfere with his functioning, and is therefore forced to remain behind. The Doctor and Turlough set off alone and soon meet the expedition, and despite the sailors’ suspicions, the Doctor assure them that he will not dispute their prior claim to the Moon; he is simply here to help. Unfortunately, Granby is beyond help; his body is found in a nearby clearing, his brains removed through a hole punched in his head. A pack of animals like a cross between giant spiders and jellyfish then descends upon the expedition, pursuing them back through the jungle. The sound of gunfire attracts reinforcements who help the sailors dispose of the animals, but the Doctor is puzzled by the predators’ unnatural behaviour; they kept pursuing the expedition long after the benefit of consuming them was outweighed by the energy expended to catch them. On their way back to the landing site, the expedition stumbles across what appears to be a long-abandoned vacuum gun, made of low-tech materials and intended to fire projectiles out of the crater. Setting aside the mystery for another time, they return to the ships, just as a miniature flying saucer arrives from the alien citadel to investigate the new arrivals. The saucer scans the ships and landing party, and then plucks up Emily and Captain Haliwell and carries them back to the saucer before the sailors can stop it. The shock of his daughter's kidnapping combined with his recent exertions kills Bryce-Dennison with a massive heart attack. Sinclair orders the Draco to pursue the saucer, but a plasma cannon mounted on the citadel opens fire and shoots the Draco down in the jungle. The Doctor offers to use his own ship to rescue Emily and Haliwell, but when he and Turlough return to the TARDIS they find that the inhabitants of the citadel have increased power to the atmospheric shield to prevent the British from escaping and that a side-effect of the shield's power is preventing the TARDIS from dematerialising. They must return to the British, and prepare to make their way through thirty miles