Episodes
| Episode | First Broadcast | Repeated | Comments |
|---|---|---|---|
| 01 | 20110516 | 20121014 (BBC7) 20140323 (BBC7) 20140324 (BBC7) | The Time Lord is reunited with Nyssa, who is on a mission to discover an anti-virus. |
| 02 | 20110517 | 20121021 (BBC7) 20140330 (BBC7) | The time travellers learn more about the base's crew and the planet's only species. |
| 03 | 20110518 | 20121028 (BBC7) 20121029 (BBC7) 20140406 (BBC7) | The Doctor realises how the base's computer will affect their fates, present and future. |
| 04 | 20110519 | 20121104 (BBC7) 20121105 (BBC7) 20140413 (BBC7) | With the base facing destruction, the Time Lord battles to secure the anti-virus. |