Wessler began writing for Atlas Comics in November 1950 with the six-page story "The Mad Monk" about the historical figure Grigori Rasputin, published in "Amazing Detective Cases" #6 (May 1951). He soon became Atlas' primary crime fiction writer, often scripting entire issues of "All-True Crime", "Amazing Detective Cases", "Crime Can't Win", "Crime Exposed", "Crime Must Lose", "Justice", and "Kent Blake of the Secret Service". Going on staff in 1952, he became a member of the Atlas bullpen with fellow writers Hank Chapman, Ernie Hart, Paul S. Newman, Don Rico and, on teen-humor comics, future "Mad" cartoonist Al Jaffee. Wessler wrote horror/fantasy stories for such titles as "Adventures into Terror", "Adventures into Weird Worlds", "Astonishing", "Mystic", and "Suspense", later adding to his body of work such war comics as "Battle", "Battle Action", "Battlefield", "Combat", and "Men's Adventures".