As the Doctor, Liv and Helen explore the universe, they come across lost souls, troubled minds and long-kept secrets. From a lonely world with birdsong but no birds, to an English university whose undergraduates tell ghostly tales, and a distant galaxy where a utopian society lives in the shadow of enormous creatures, the TARDIS crew are haunted by echoes of past, present and future...

Birdsong by Tim Foley.

The TARDIS arrives on an empty world where two scouts await the rest of their colony. Except this world may not be as empty as everybody thinks. There's a figure in the woods - and a strangely familiar sound... As the Doctor and his friends learn more about the planet's inhabitants, the birdsong they hear becomes a deadly chorus.

Lost Hearts by Lauren Mooney and Stewart Pringle.

Michaelmas term, 1903. In one of England's ancient universities, strange apparitions float between quads and cloisters. While Liv and Helen protect a naive undergraduate from a sinister society, the Doctor finds a ghost-hunting ally. One who happens to be the era's foremost chronicler of things that go bump in the night...

Slow Beasts by Dan Rebellato.

The Doctor takes Liv and Helen to see one of the Wonders of the Outer Galaxy - to Ran-Zoan, where immense alien figures loom over the plains and settlements of the Renn. But the Slow Beasts hide a secret - a secret that, once unleashed, spells doom for this entire world.

CAST: Paul McGann (The Doctor), Nicola Walker (Liv), Hattie Morahan (Helen), Jane Asher (Myra), Derek Griffiths (Mathryn), Fiona Button (Bex), Steve Brody (Monty James), Joe Pitts (Robert Sinclair), Timothy Bentinck (Professor Alistair Gray), Maya Saroya (Iri / Bartha), Dan Starkey (Calthrys / Valryth / Cha-Harr), Holly Jackson Walters (Zythrev). Other parts played by members of the cast.