Summer Falls (novel)

 was an e-book released to coincide with TV: The Bells of Saint John. It was based on Summer Falls, an in-universe book featured in the episode that was meant to be written by Amelia Williams.

Publisher's summary
"When summer falls, the Lord of Winter will arise..."

In the seaside village of Watchcombe, young Kate is determined to make the most of her last week of summer holiday. But when she discovers a mysterious painting entitled 'The Lord of Winter' in a charity shop, it leads her on an adventure she never could have planned. Kate soon realises the old seascape, painted long ago by an eccentric local artist, is actually a puzzle. And with the help of some bizarre new acquaintances - including a museum curator's magical cat, a miserable neighbour, and a lonely boy - she plans on solving it.

And then, one morning Kate wakes up to a world changed forever. For the Lord of Winter is coming - and Kate has a very important decision to make.

Characters

 * Kate Webster
 * Kate's mother
 * Grey cat
 * The Curator
 * Armand Dass
 * Mrs Groves
 * Mr Dass
 * Milo Mitchell
 * Brewster
 * The Lord of Winter

Continuity
At the end of The Day of the Doctor (TV Story), the Fourth Doctor (portrayed by Tom Baker) appeared as The Curator, explaining to the Eleventh Doctor (portrayed by Matt Smith) that "Gallifrey Falls No More".