The Third Doctor wakes up in a strange place. He seems to be in a cell. He finds a device constructed out of spare parts and a bunch of library books in the cell. He speaks out loud and notices his voice sounds funny. He starts to rub his chin and realises he has a beard. He uses a shiny book cover as a mirror, and sees that he is in the Master’s body.

Meanwhile, the Master wakes in the Doctor’s laboratory…