The origin story of The Shield appeared in "Shield–Wizard Comics" #1 (Summer 1940). He is really chemist Joe Higgins, the son of Lieutenant Tom Higgins. Tom was working on a chemical formula for super-strength which the Germans were after, and is slain by German saboteur Hans Fritz in the Black Tom explosion, for which Tom was blamed. After Tom's death, Joe continues to work on it while continuing his studies of chemistry. Joe finally figures out the solution, which requires applying the chemicals to certain parts of his anatomy (Sacrum, Heart, Innervation, Eyes, Lungs, Derma), and exposing himself to x-rays. This gives him super strength, the ability able to make great leaps, and invulnerability. Joe uses the initials S.H.I.E.L.D. as his secret identity. His white costume becomes the familiar colors under the process. He becomes an FBI agent (whose secret identity is known only to FBI Chief J. Edgar Hoover) after clearing his father's name, and fights foreign agents and other threats to the U.S. At the start of the strip, Higgins' partners are fellow G-Man Ju Ju Watson, and girlfriend Betty Warren.