Season 1978, Episode 1: Murder Under Glass - Food critic Paul Gerard poisons restaurateur Vittorio Rossi with fugu-laced wine to prevent exposure of his extortion racket. Columbo deduces the poison was delivered via a swapped bottle opener. Gerard attempts to poison Columbo, but the lieutenant reveals he anticipated the trap, securing **Gerard'

Season 1978, Episode 2: Make Me a Perfect Murder - Ambitious TV executive Kay Freestone murders her lover and boss, Mark McAndrews, after he denies her a promotion and ends their affair. She meticulously stages an alibi using a film projection booth and the building's elevator system. Columbo unravels her intricate plan by exposing how she manipulated the film footage counter and revealing the recovered murder weapon from the elevator shaft, leading to her arrest.

Season 1978, Episode 3: How to Dial a Murder - Dr. Eric Mason, a behavioral psychologist, seeks revenge on Dr. Charles Hunter for an affair with his late wife. Mason trains his Dobermans to kill on command using a phone and the code word "Rosebud," resulting in Hunter's violent demise. Columbo exposes the plot by revealing he reprogrammed the dogs to respond with affection, foiling Mason's plan.

Season 1978, Episode 4: The Conspirators - Irish poet Joe Devlin, secretly a gunrunner, murders arms dealer Vincent Pauley when Pauley attempts to double-cross him on a weapons shipment for the IRA. Lieutenant Columbo investigates, connecting Devlin to the crime through subtle clues, including unique scratches on whiskey bottles made by Devlin's ring. Columbo ultimately exposes Devlin's guilt and thwarts the illegal arms delivery, leading to Devlin's arrest.