The Twisted Trap
M. E. Chaber
Published in Bluebook For Men, June 1961. Part of the collection .
"Just because you’re paranoid doesn’t mean they’re not out to get you. A wealthy old policyholder claims that his sexy young wife and her psychiatrist lover have teamed up to poison him with a drug that mimics the symptoms of madness. If he should die “accidentally” as a result of this condition, his wife will get an enormous life insurance payout. Having escaped from a sanatorium, the old man insists that Milo must rescue him. But doing so may cost Milo his own sanity!"