As Megan Jones is about to arrive, Harris returns to the centre and informs her of the situation, but she doesn't believe him. He also prioritises the capture of Robson, who is found sedated in his room, and Megan Jones demands to see him. He has sunk into a depressed state but briefly rallies and begs his old friend to help him. They leave him and he rests. On awakening, the heartbeat sound returns to his head, and he heads off. Within minutes, he finds Victoria and takes her hostage. He forces her into a helicopter and flies it out to sea. Now terrified, Megan Jones tells the Doctor to do whatever he can. The seaweed has pumped itself up into the impeller pipe in the impeller room and is soon expanding and throbbing. It bursts the pipe and starts to fill the rooms. The Doctor commandeers a helicopter and travels with Jamie to the rig where Victoria has been taken, where they find Robson mostly transformed into a seaweed creature. He says humanity is doomed and tries to gas the Doctor with his breath. Jamie has meanwhile found Victoria. When she sees Robson's form she starts screaming, which appears to distress and disable Robson, and they all escape.