A finder's magic - Philippa Pearce

A mysterious stranger called Mr Finder offers to help Till find his dog, and they interview various witnesses including a heron, a mole, a riddling cat - and Miss Mousey, whose sketch of a peaceful riverbank offers a vital clue. The quest to find Bess is full of magic but Till begins to mistrust his supposed ally Mr Finder - until at last he realizes the truth, and they track down the real culprit,a finder who likes to keep what he finds. At the end of this enchanting story Till is reunited with his beloved Bess and a new book - of the story - will be born.