Season 1972, Episode 1: Short Fuse - Eccentric chemical heir Roger Stanford murders his uncle, David Buckner, and chauffeur Quincy by rigging a cigar box with explosives to prevent his uncle from selling the family business and exposing Roger's misdeeds. Columbo suspects foul play after noticing Roger's unusual behavior. In the climax, Columbo confronts Roger in a cable car with a seemingly harmless cigar box. Roger, believing it's still booby-trapped, panics and attempts to dispose of the cigars, inadvertently confessing his guilt.

Season 1972, Episode 2: Blueprint for Murder - Architect Elliot Markham murders wealthy industrialist Bo Williamson to secure funding for his ambitious "Williamson City" project. Columbo investigates Williamson's disappearance, suspecting foul play when no body is found. After navigating bureaucratic hurdles, Columbo orchestrates the excavation of a concrete pylon at the construction site. Williamson's body is discovered entombed within the pylon, exposing Markham's crime.

Season 1972, Episode 3: Étude in Black - Symphony conductor Alex Benedict murders his mistress, pianist Jenifer Welles, to prevent her from exposing their affair and jeopardizing his career. He stages her death as a suicide by gas. Lieutenant Columbo investigates, finding inconsistencies, particularly a dropped boutonnière at the scene. Benedict's alibi crumbles under Columbo's scrutiny, and his wife refuses to corroborate his story, realizing his guilt and leading to his implied confession.

Season 2, Episode 2: The Greenhouse Jungle - Wealthy orchid collector Jarvis Goodland orchestrates a fake kidnapping with his nephew, Tony, to access Tony's trust fund. However, Jarvis murders his nephew to claim the entire inheritance for himself. Lieutenant Columbo investigates the supposed kidnapping, which quickly turns into a murder case. Columbo ultimately exposes Jarvis's scheme by revealing a crucial extra bullet fired in the greenhouse, linking Jarvis directly to the crime.

Season 2, Episode 3: The Most Crucial Game - Football team general manager Paul Hanlon murders owner Eric Wagner by striking him with a block of ice at his poolside, staging it as an accidental drowning. Hanlon creates an elaborate alibi using a faked phone call and bugged house phones during a game. Columbo unravels the plot by noting fresh water around the pool and ultimately exposes Hanlon when a replay of his alibi phone call lacks the expected chime of a cuckoo clock, proving his deception.

Season 1972, Episode 6: Dagger of the Mind - While in London, Lieutenant Columbo investigates the death of Sir Roger Haversham, a theatrical producer. Shakespearean actors Nicholas Frame and Lillian Stanhope accidentally kill Sir Roger during an argument and stage it as an accident. When their butler, Tanner, attempts to blackmail them, they murder him and fake his suicide. Columbo ultimately exposes their guilt by demonstrating how a pearl from Lillian's broken necklace ended up in Sir Roger's umbrella, proving the initial death was no accident.