Trying to rescue the Doctor from the Tractator's trap, Tegan lands them both in even more trouble. Turlough goes a bit mad, and reckons he knows the evil of the Tractators from old.

The Doctor and Earl manage to escape from the Kandy Man and join up with the planet's natives, the Pipe People, enlisting their help to rescue Ace.

As the Doctor leads the Pipe People towards reclaiming their world, Helen A faces betrayal from those closest to her.