This is sort of a strange story, but I think that such can be said of most Ellery Queen mysteries. In any event, I've read them all and this is one of the three best that "the two cousins," (Nathan, a.k.a. "Dannay," and, Lepofsky, a.k.a. "Lee"), ever wrote.
Ellery and his dad, Inspector Queen of the NYPD, are enjoying a much-needed touring vacation through the Western U.S. They get lost on a rutty backroad when a forest fire breaks out and forces them to a strange old mountaintop mansion. There, they find a renowned physician living in seclusion with a weird parade of family, staff, and guests.
As the fire encroaches each day upon the mountain, the suspense builds and, of course, murder ensues. It's up to Ellery and his dad to sort through the bizarre cast of principals and put the finger on the guilty party.
It would be a bit of a spoiler to reveal the precise nature of the title but, leave it to say, it's one of the strangest facets of the mystery.
Don't pass this one by, even though it's a fairly old volume. It's a superb rendering with lots of atmosphere and detailed clues, both of which are so indigenous to the great Ellery Queen mysteries.