According to Agatha Christie, Black Coffee stays true to the saying that “the truth is never horrible, only interesting.”
Her website summarises the plot as follows:
“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.”
The play develops into a humorous investigation that baffles audiences. Just when you think you understand how Detective Poirot’s mind works, he shocks you into disbelief. And, just when you think you know who the killer is, a plot twist leaves you reeling with confusion.