Concurrent with drawing Iron Man, Heck succeeded Jack Kirby as penciler on the superhero team series "The Avengers" with issue #9 (Oct. 1964), the introduction of Wonder Man. The Count Nefaria character was introduced by Lee and Heck four issues later. Heck, who inked his own pencils for many years, transitioned to the "Marvel method" of doing comics — in which the penciler plotted and paced the details of a story based on a synopsis or plot outline from the writer, who would afterward add dialog — and was assigned the help of an inker for the first time. He successfully made this adjustment, and went on to make "The Avengers", which he drew through issue #40 (May 1967), plus the 1967 annual, one of his signature series. He inked his own pencil work in issues #32–37.