- Jodie Whittaker (The Doctor)
- Mandip Gill (Yasmin 'Yaz' Khan)
- John Bishop (Dan Lewis)
Episode: 42
Air Date: 2007-05-19
Runtime: 48 min
In a far-flung galaxy, saboteurs are at work, and crew members are being possessed. The TARDIS crew find themselves in the 42nd century on a spaceship, SS Pentallian, slowly being pulled into a sun, and must find a way to survive