The Doctor, Nyssa and Tegan find themselves trapped in history - and discover that even the most familiar of pasts can still conceal surprises.

1. Pursuit of the Nightjar by Tim Foley (4 parts)
The story of the Nightjar has been told for many years. A spaceship helmed by the legendary Captain Goben on a vital mission of mercy, delivering medical supplies to a distant colony in the middle of devastating war, an act of bravery that triggers the end of the conflict.

At her heels throughout the journey, her pursuer, the spaceship Nemesis, helmed by the dogged Captain Eslo, never quite able to catch her target. The Doctor has always wanted to witness these historic events. And now, alongside Nyssa and Tegan, he's got his chance.

But history might just have other ideas.

2. Resistor by Sarah Grochala (2 parts)
The TARDIS lands in a basement beneath a club in Warsaw in 1982 - which is a bit of a surprise as the Doctor was hoping to take Nyssa and Tegan to Yugoslavia.

But a bigger surprise is yet to come - the band on stage are missing one of their musicians. And getting them through the gig is only the start of the TARDIS crew's troubles.

Something strange is happening on the streets. Black cars glide through the city, picking off the unwary. Some are driven by the Secret Police... but others... by something very much not of this world.