Dearly beloved, we are gathered here today to pay our respects to the detective fiction novel Halfway House (1936) written by Manfred Lee and Frederic Dannay under their Ellery Queen nom de plume. As the title suggest, there will be spoilers - lots and lots of spoilers, so only proceed if you've done the necessary pre-reading...
via #446: Spoiler Warning 8 - Halfway House (1936) by Ellery Queen - The Invisible Event