The Horror of Hy-Brasil (audio story)

 was a short trip featuring the Second Doctor, Jamie, and Zoe which was available to subscribers of Big Finish's main Doctor Who range whose subscription included Shadow Planet / World Apart.

Plot
While the Doctor and Zoe prepare an ‘un-birthday’ surprise for Jamie, the Highlander wanders outside the TARDIS to find himself in what he takes to be Scotland, 1748. As Jamie chases after a Will o the Wisp, the TARDIS is displaced in time and space, transporting the Doctor and Zoe to an aquatic research station in a pocket universe. Exploring the floating complex, the duo find Jamie, apparently frozen in time; Zoe meddles with some controls, aligning her and the Doctor with the slower time-rate aboard the base, but preventing them from returning to the TARDIS. A PA announcement tells them they are on Hy-Brasil, which Jamie recalls is a phantom island of Celtic legend. The travellers are greeting by humanoid creatures named Balor and his daughter, Eithne, two Formorians who are searching for a cure to their race’s sterility, caused by the temporal radiation from the base’s engines. While Balor tries to persuade the Doctor to explain the secrets of his TARDIS, Eithne shows Jamie and Zoe her hydroponics laboratory. Eithne reveals that she introduced heather to Earth, by genetically combining local and Formorian plants; while she was tending the plants, Jamie mistook her for a Will o the Wisp, and was caught in the time-field of Hy-Brasil. Exploring the base, Zoe finds a secret area full of horrific animal hybrids, victims of Balor’s monstrous chimeric experiments. Deducing that Balor used his own wife for his genetic experimentation, the Doctor escapes and finds Jamie and Zoe, just as Eithne is reunited with her mother, now a Fomorian-deer hybrid. Balor intervenes, and after using his weapon to de-evolve his wife into primordial soup, he forces the Doctor into a disintegration capsule, to transfer his energy into Eithne. However, before the transfer is activated Jamie breaks the Doctor’s capsule, causing Eithne to transform into a hideous creature. Now aware of her father’s terrible actions, the misshapen Eithne sets the auto-destruct on the base and frees the TARDIS, allowing the Doctor and his friends to escape moments before the Fomorian base explodes. Returning to the normal universe, the TARDIS arrives in Ireland, where the Doctor, Jamie and Zoe reflect on how the Fomorians live on in the countryside heather…

Characters

 * Second Doctor
 * Jamie McCrimmon
 * Zoe Heriot

Continuity

 * Jamie refers to the Doctor dematerialising the TARDIS to escape a volcanic explosion occurring on Dulkis. (TV: The Dominators)
 * The Doctor moved a dusty backgammon board to open a plant incubator. During his first incarnation, the Doctor played backgammon with Kublai Khan. (TV: Marco Polo)
 * The Fomorians reappear. (PROSE: Eve of the Fomorians)