Heck became an Atlas staff artist on September 1, 1954; his first known work for the company was the five-page horror story "Werewolf Beware" in "Mystery Tales" #25 (Jan. 1955), though Heck in 1993 recalled, "The first job I did was about a whale breaking a ship apart. Then I did submarine-crew feature 'Torpedo Taylor' for "Navy Combat"," drawing that five- or six-page feature in issues #1–14 and 16 (June 1955–Aug. 1957, Feb. 1958) and, oddly, doing one page of a five-page story finished by Joe Maneely in issue #19 (Aug. 1958). Until Atlas' 1957 business retrenchment — when it let go of most of its staff and freelancers and Heck spent a year drawing model airplane views for Berkeley Models — Heck contributed dozens of war comics stories and Westerns plus a smattering of jungle and science-fiction/fantasy tales.