Brings back several characters from an earlier novel, The Secret of Chimneys, in a story that can best be described as a John Buchan thriller told by P.G. Wodehouse. (https://agathachristie.fandom.com/wiki/The_Seven_Dials_Mystery)

Consummate young silly ass Gerry Wade is the despair of hosts and hostesses across the land, with his inability to make it to breakfast before the eggs are congealed, the toast has wilted and the coffee has grown chill and distinctly unwelcoming. And so, a small group of sundry other young silly-asses and interchangeable girls decide that a good, stiff dose of eight fine alarum clocks would be just the thing to spring him, yelling, from his bed in the early hours. This plan, however, fails signally to work, for the very good reason that Gerry is far too dead to be roused by anything quieter than the Last Trump.
This discovery both puts a dampener on the house party and raises some questions. Why would a notoriously heavy sleeper die of an overdose of a sleeping draught? And why are there only seven of the eight clocks found in the bedroom, neatly and sinisterly arranged on the mantelpiece as though to convey some message?
Lady Eileen ‘Bundle’ Brent and friends are shortly to find out… (https://alackofconsensus.wordpress.com/2018/03/07/review-the-seven-dials-mystery-by-agatha-christie/)