Earth Transit by Charles L. Fontenay
On the Marsward IV, seventy-three days into a Mars-bound flight, astrogator Lefler wakes forty minutes late for his watch and finds Captain Makki dead in the control room, killed by a heat-beam burn to the chest, his gun drifting loose nearby and, oddly, gloves on his hands. With only three men aboard — Lefler, ship's doctor Taat, and engineer Robwood — one of them must be the killer, and each has reason to have wanted the tyrannical, contemptuous Makki dead. Lefler radios White Sands, assumes command, and secures the body outside the airlock to preserve evidence. He hides the heat-gun to protect any fingerprints and begins piecing together the crime while continuing his astrogation duties, including tracking the ship's Earth transit — a periodic astronomical observation that becomes the story's crucial timekeeping device. Each crew member dictates a statement: Robwood reveals Makki once wrecked his engagement out of spite; Taat admits a soured business partnership with Makki over dome-enterprise stock. Both men profess innocence and needle each other with suspicion, while privately each also seems relieved Makki is gone. Haunted by a half-remembered nightmare of violence toward Makki from childhood, Lefler begins to suspect he himself may have killed the captain in a sleepwalking rage — his bunk straps had mysteriously come undone before he woke. Taat, reviewing the timeline with clinical detachment, presents a home movie of a laboratory experiment with mice that he filmed continuously during the estimated window of the murder, which seems to alibi both himself and Robwood, leaving Lefler as the only crew member unaccounted for. Shaken, Lefler nearly turns himself in for arrest. But re-checking the ship's log, Lefler realizes Taat's film began at a suspiciously precise hour and that Taat's stated time of death does not square with the log: the Earth transit itself began at a documented time, and Makki — meticulous to a fault — never recorded it, meaning he was already dead before Taat claims to have last seen him alive. Confronting Taat with a heat-gun, Lefler exposes the false timeline. Taat, cornered, attacks; in the struggle Lefler is forced to fire, mortally wounding him. Dying, Taat confesses: Makki had cheated him out of savings meant to fund a clinic on Mars, drew the gun in a confrontation, and was killed in the ensuing struggle — after which Taat staged the scene, planted the gloves, and fabricated his alibi film's timestamp to suggest suicide and deflect suspicion, at one point even loosening Lefler's bunk straps to make him doubt his own innocence. With the confession radioed to Earth to clear both surviving crewmen, Lefler returns to duty, still bound by protocol and the machinery of the voyage, to record the transit's midpoint in the log.
By Charles L. Fontenay · First published 1957 · Genre: Science Fiction Mystery, Locked Room Mystery, Detective Fiction