As I write this book review, I am still excited at having solved this mystery, not simply by guessing, but largely through careful deduction. My reasoning was not entirely flawless, nor as systematic and precise and complete as the final explanation by Ellery Queen, but it was sufficiently exacting to warrant some self-praise. I did take the author's suggestion and set the book aside for several hours and wrestled with the conundrum before looking at the final chapter.
The Spanish Cape Mystery is classic Ellery Queen: a superbly crafted mystery with intriguing characters, a rather remarkable setting, and a concluding exercise in impeccable logic. The title refers to both the fictional setting, a small rocky peninsula on the New England coast, and a key element in the mystery, a rather flamboyant item of dress.
Ellery Queen mysteries are entertainingly written, but are not as literate as works by P. D. James or Colin Dexter. However, as his fans have come to expect, Ellery does sprinkle his conversation with literary and poetic quotations. Look for Voltaire, Bacon, Keats, Coleridge, La Rochefoucauld, Germaine de Stael, and William Collins in The Spanish Cape Mystery. We also occasionally meet examples of Ellery's vocabulary excesses like natatorial habits and prestidigitating deductions.
Although The Spanish Cape Mystery was first published in 1935, it has been reprinted many times, and a paperback version is readily available through Amazon.com. Apparently, The Spanish Cape Mystery is also available on audio tape.
If you enjoy trying to unravel a carefully constructed mystery, I highly recommend Ellery Queen`s many excellent stories. The Spanish Cape Mystery would make a good introduction to Ellery Queen for the reader that has yet to have the pleasure of his acquaintance.