[sufue]

Black Coffee is a novelized version of an Agatha Christie play, featuring Hercule Poirot - and, of course, Captain Hastings as well. It was novelized by Charles Osborne. It's on sale for £0.99 at Kindle UK, but not on sale at Kobo UK, at least as of now, but could probably be price-matched.

Kindle UK: https://www.amazon.co.uk/dp/B004BDOTMC
Kobo UK (for price check/match): https://www.kobo.com/gb/en/ebook/black-coffee-poirot

Spoiler:

A full-length Hercule Poirot novel, adapted from Agatha Christie’s stage play by Charles Osborne

Sir Claud Amory’s revolutionary new formula for a powerful explosive is stolen. Locking his house-guests in the library, Sir Claud switches off the lights to allow the thief to replace the formula, no questions asked. When the lights come on, he is dead, and Hercule Poirot and Captain Hastings have to unravel a tangle of family feuds, old flames and suspicious foreigners to find the killer and prevent a global catastrophe.

BLACK COFFEE was Agatha Christie’s first playscript, originally performed in 1930 and made into a now rarely-seen film the following year. Combining her typically beguiling plot and sparkling dialogue with his own faithful narrative, Charles Osborne’s novelisation is ‘A worthy addition to the Christie canon’ (The Spectator)