Robert Bruce Montgomery (1921-1978) wrote comic mystery novels under the pen name of Edmund Crispin, the first of which, "The Case of the Gilded Fly," was published in 1944. Crispin didn't write many novels, but those he did featured the eccentric, absent-minded Oxford don and professor of English and Literature, Gervase Fen.
The third of these books is perhaps his best. Titled "The Moving Toyshop," PD James named it as one of the best five mysteries of all time and critic and mystery writer H.R.F. Keating included it among the 100 best crime and mystery books ever published. Keating added, "The word to describe The Moving Toyshop is 'rococo'. It possesses in splendid abundance the ebullient charm of the works of art thus labelled. It is alive with flourishes. Its mainspring the actual disappearance of a toyshop visited in midnight Oxford, has all the right fancifulness, and at the end it is explained with perfect plausibility."
The plot centers on poet Richard Cadogan, who stumbles on the dead body of an old lady in an Oxford toyshop late one night right before a blow from an unseen assailant knocks him unconscious. But when he recovers, not only has the woman disappeared, the entire toyshop has vanished, replaced by a grocery store. When the police not surprisingly refuse to believe Cadogan's story, he turns to the only person he thinks can help, his former colleague Gervase Fen. Fen's response is a typical Crisin ploy, a breaking of the fourth-wall illusion, "It's somewhat unusual business, isn't it." "So unusual," replies the poet, "that no one in his sense would invent it." (At another point, Fen dreams up book titles "for Crispin.") Fen sets about solving the impossible crime via his intuition, wits and wit, tossing in various literary references and quotations along the way, including clues based on Edward Lear limericks.
Crispin unfortunately suffered from a problem with alcoholism, and it was his drinking that eventually made into an invalid and semi-recluse, too weak to write. It's a shame, for it would have been interesting to see where his imagination and whimsical take on the genre would have led him, had he had full use of his faculties. The Fen books are witty, clever and entertaining, and filled with wonderfully eccentric characters.
FYI, the Felony & Mayhem Press reprinted several titles in the Fen series, including a new edition of The Moving Toyshop just last year, adding to an audio book from Audible in 2008.