Ellery Queen mystery set in New York City

n Days' Wonder [hardcover] Queen, Ellery [Jun 01, 1948] …

"Ellery had a simple case. A few days of discreet snooping, some choice advice, and the inimitable sleuth would blithely restore domestic harmony to the millionaire couple Dirk and Martha Lawrence. And then came the scarlet letters. And finally the cryptic clue...scrawled in a murdered man's blood. A simple case? Unless Ellery did some super-fast sleuthing, he'd have nothing to show but a very scarlet face."

8vo size hardcover