Tom Skerritt plays Dude Donaldson: dressed as rodeo clowns, he and an accomplice rob a rodeo (rather brutally, killing half-a-dozen people). Cannon is summoned to figure out what's going on, after authorites spend 6 weeks and come up with nothing. There's a home movie taken at the time of the robbery, in the vicinity of the buliding... Cannon and the others watch this film over and over, like the Zapruder film, and eventually it dawns on Cannon that the clowns may be involved. He tracks a clown suit to a Texan who died in Vietnam the previous winter... the man's widow (Sharon Acker) is less than forthcoming... though her young son (Vincent Van Patten) gives Cannon some leads... Skerritt took the suit from the widow's barn and used it in the robbery. Skerritt goes to Acker's house and threatens her and her son against saying anything to Cannon...Cannon senses what's going on, and after almost being snipered by Skerritt...finally subdues him with a bear hug.
Mike Tampa owns a vineyard in northern California... his land alone is worth $2 million, but he loves wine-making and is not considering selling. His father started the vineyards, handed them down to him, and he hopes that his son Johnny Tampa will be the third generation. Mike Tampa, however, has been the victim of three murder attempts—in the last one, his brakes were tampered with, and he barely survived when he took his car down a mountain road. At this point, his secretary calls on Cannon—secretly, because the stubborn Mike has refused to do anything. Cannon is brought in to investigate. We learn that Johnny Tampa had only been re-united with Mike two years ago... after not having seen him for 20 years (Mike and his wife went through a bitter divorce 22 years prior and she took their son down to San Francisco). Cannon suspects that Johnny may be pulling a con and that he is not really Mike's son. The winery accountant says that they had Johnny checked out by a PI down in SF n
Dale and Laura Corey are a happily married couple who own an electronics store; he does a lot of electronic eavesdropping for clients, she was a cop on the force with Cannon a few years back, and hires him because Dale is being threatened after bugging some hotel rooms for the owner and catching three guests in compromising positions. The three are being blackmailed, and think Dale is behind it. Cannon interviews them and determines that one of the three is blackmailing the other two.
Toby Hauser is a compulsive gambler who is $200,000 in debt to Ben Logan (who runs local illegal gaming operations). The bill is due and Hauser has about $5000; they threaten to come after Hauser's wife Cathy if payment isn't made. Toby will turn himself over to Logan rather than have anything happen to Cathy, who, sensing one of them will be hurt, calls in Cannon to help. Cannon tries to broker a deal with Logan. Cannon can get $25,000 paid up front and the rest on installment. Logan rejects this deal, because it would ruin his reputation if anybody got a break like that. Jason Logan (Ben's son) runs a gambling operation on his own—competing against his father in a juvenile attempt to come out from his father's shadow. Toby takes one last shot to get the $200,000. He shows up at Jason's house to get in a poker game. Jason has a couple of card-marking plants at Toby's table, but Toby gets $35,000 ahead. Then Cannon shows up undercover as Billy Thompson (owner of Thompson Tool),
Frank Cannon and Barnaby Jones investigate the rape and murder of a young woman who was about to blow the whistle on the company she was involved. But they are investigating for different clients and from totally different angles. [NOTE: Part two of this story continues on the TV series "Barnaby Jones.]
Private detective Frank Cannon comes out of retirement to investigate the murder of an ex-girlfriend's husband.
Cannon and Jones try in vain to convince Lt. Biddle that Bud McKenna's death was murder. Betty occupies Gordon's secretary Alice Parks, while Cannon searches her apartment. The detectives uncover an international conspiracy and escape two attempts on their lives.