The Doctor and his great-grandson Alex have been reunited amid the Time War. Splintered timelines draw them ever closer to another fellow traveller. Does Cass's destiny lie in the TARDIS?

As the Time War rages, the Doctor enters uncharted territory - where any 'friends' they meet might not be what they seem...

6.1 Nowhere, Never by Katharine Armitage
Cass is lost. In her place, a suburban housewife counting the hours until her family returns. But terrifying air raids are ripping through her calm.

The Doctor and Alex are trapped - patients in a strange hospital run by a fearsome Matron. They've both been injured in a war, but neither remembers exactly which war...

They all soon realise that time is not on their side.

6.2 The Road Untravelled by Tim Foley
The Doctor, Alex and Cass find themselves on board a strange ship in an even stranger environment.

It's a place where friends might be enemies, or worse. Where even time cannot be relied upon. And something is out in the Void, following them. Their troubles are only just beginning...

6.3 Cass-cade by James Moran
Cass is falling through the timestream of the Universe, splintered in chronology. She keeps encountering the Doctor and Alex, but for them, it's the first time they've met her, each time.

Cass must fight to centre herself, fight for her existence, and fight for her friends to even remember her.

6.4 Borrow or Rob by Tim Foley
The Doctor and friends are traversing the Void, pursued by unknown forces – and their grip on reality is becoming ever more tenuous. As the enemy boards their ship, Alex and Cass edge closer to the truth. And the Doctor faces the consequences of his choices...