Inconstancy

The Story Demon by Julian Richards
The Doctor and Mrs Clarke find themselves on a forest world where human settlers shelter from the night in a village built from wrecked spaceships, living in fear of the Birnamen, creatures who raid their settlement leaving death in their wake.

But are the Birnamen really to blame? Or does the truth lie with the villagers' 'Story Demon', the hollow travel casing of a very familiar alien creature which they use to entertain their children...

The Key to Many Worlds by Paul Magrs
The Doctor and Constance arrive in thirteenth century Baghdad and encounter an ageing and disenchanted Marco Polo. His adventures at an end, he has been ordered to transport a certain enchantress back to the Doge's palace in Venice. The Doctor realises his danger too late, as his mind is swapped with that of the enchantress - the notorious Iris Wildthyme!

Now clapped in irons and trapped in Iris's form, the Doctor is dragged along in Marco's caravan as it trails across the desert once more... and only Mrs Clarke can save him.

Inconstancy by Ian Potter
On the highly regulated colony world of Hoi, the Doctor is captured by the authorities and taken to the forbidden zone for 're-education'. Mrs Clarke escapes and discovers an amorphous being in hiding. This protean creature craves purpose and identity, and wants Constance to make it an instrument of her will. Desperate to rescue the Doctor, she agrees - and suddenly Hoi is threatened by a swarm of wild and ravenous Mrs Clarkes!

978-1-80240-596-5

1 out of 6 (16.7%) raters say this story requires a previous story.