Big Shamus, Little Shamus

Max eavesdrops on a phone call in which a hired killer is to murder Korman for revenge. Korman investigates with his computer, Arnie, who has common sense.

Arnie unintentionally exposes a woman given a new identity by the FBI, and he now must protect her from the mob.

Through Max's relationship with Paul, the Bar Mitzvah boy, Arnie learns Paul's mother is being blackmailed. When the blackmailer is killed, both Paul's mother and her husband come under suspicion.

The insurance agent for a company arranging a ""buy-back"" of a Rubens is mugged. Arnie becomes suspicious when the thief seems to know the insurance agent, and Arnie's investigation almost gets him killed.

The diversion at the heist of a jeweler's trade show, an attempted suicide, is diverted by Max's friendship with the woman's daughter.

Stephanie's cousin convinces Stephanie and Arnie to help him one last time. Only this time his con game kills a cop and almost kills Max.

Arnie and a young heiress are held hostage en route to Max's Father's Day speech at school.

Arnie becomes romantically involved with a beautiful singer who is making a comeback. A fake attempt on her life, staged for publicity, becomes twisted and the attempts become real.