A cheap-and-cheerful collection of all of Sayers' short mysteries -- which includes a lot of Lord Peter Wimsey stories, rather fewer Montague Egg stories (he's a travelling salesman who -- no great surprise -- solves mysteries), and a handful of standalone mysteries. The only thing it's missing is "The Wimsey Papers", which aren't really stories as such.
This collection really makes Sayers' skill at inventing mysteries obvious -- nearly all of the Wimsey stories could have been worked up to book length. (Indeed, one was; "The Unsolved Puzzle of the Man with No Face" is clearly an earlier version of "Have His Carcase", albeit with a different resolution.) Many of the stories here are rather more light-hearted than the usual Wimsey fare, though, which may not be entirely to the reader's taste.
Recommended for those who've enjoyed Sayers' full-length mysteries and are looking for a collection of ten-minutes diversions along the same lines.