***SPOILERS*** The kind respected and beloved town psychiatrist Dr. David Craig, Dick Foran, finds himself in the eye of the storm in this Perry Mason episode. That's in Dr. Craig recording his patients problems as part of his therapy for them. It's when Dr. Craig's secretary Edith Douglas', Marianne Stewart, degenerate gambler kid brother Mark, Barry McGuire, finds out that he's been treating big time plane manufacture Peter Heywood, Philip Terry, for depression over his failing marriage that he, in having an extramarital affair, in fact is responsible for he schemes to get his sister to get him the recordings of Heywood's sessions. Mark plans to use them to blackmail Heywood in order to get the $4,000.00 he owes the mob run casino he's been gambling at.
With Edith making a wax impression key to Dr. Craig's safe where he keep the tape recordings Mark now uses them to both blackmail Heywood as well as his wife Barbara, Andrea King, by having her pay for the recording so she can use them in a future divorce settlement. It's when Mark is found shot to death in his apartment by Perry and his in house private eye Paul Drake, William Hopper, that all the evidence points to the good doctor and psychiatrist! Since just a few hours earlier Dr. Craig threatened to shoot Mark, who made a number of copies of them, for stealing his personal audio tapes! It's now up to Perry Mason who's Dr. Craig's good friend as well as lawyer to track down who really did Mark Douglas in. In fact Dr. Craig did himself in real good by stupidly deep sixing his licensed .38 revolver in the Pacific Ocean making it impossible for Perry to prove, through ballistics, that his gun wasn't the one that blew Mark away!
***SPOILERS*** With all the people who would have had it in for Mark and gone so far as to murder him Perry gets that person to come out in the open not in court but at the scene of the crime. That's by tricking him or her to show up at Mark's apartment for the audio tape he hid there. Not realizing that by doing that Perry had the police waiting for the killer to not only show up but in trying to retrieve the audio tape confess to his crime as well!