This is an in-universe article with out-of-universe material.
Originally born on Earth-Two as the son of the criminal Brainwave and Gimmick Girl (who was originally written as being tricked into the relation but later openly acceptant of her husband) Hank Jr. was revealed to have inherted his father's superhuman mental abilities.
Hank Jr. would remain mostly hidden from the condemnation of his famous parents until he attained early adulthood and sought to actively pursue an active crime-fighting career in some measure to atone for his father's past deeds in his uncle, Sylvester Pemberton, Jr., the original Star-Spangled Kid who was forming a new superhero group called Infinity, Inc.. Following his father's death, he dropped the 'Jr.' from his name and began calling himself just 'Brainwave'.
Infinity, Inc. consisted of many of the direct children and successors of the Justice Society members. Despite their youth the team proved their effectiveness when they defeated their elder heroes when the Justice Society was possessed by the Stream of Ruthlessness. While a member of Infinity, Inc., Hank met and became romantically attached to Jade the daughter of Alan Scott. Despite his best attempts the relationship ended badly.
After the disbanding of the original Infinity Inc. Hank suffered a mental breakdown due to unresolved guilt issues over his villainous father and, shaving his head in order to more closely resemble his father, founded the Legion of Doom and used them to attack a branch of the Justice League. He was captured and sent for psychiatric treatment but was not cured. Black Adam used his mental instability to convince him to join his crusade to free his native Kahndaq and bring peace to Earth as Adam saw fit. During the ensuing battle against the JSA a miniaturized Atom entered Hank's head in an attempt to destroy the growth that gave him his powers. Inside Hank's head Atom found that Hank's brain was actually harboring the parasitic worm-like Mr. Mind who was using him as a source of food and development while amplifying Hank's telepathic powers and the real cause of his mental problems causing him to run amok acting villainous. Hank was saved from Mr. Mind by Atom treated by his fellow JSA members and eventually turned over to the care of his mother, Merry Pemberton.
- Although this character was originally introduced during DC's Earth-Two era of publication, their existence following the events of the 1985–86 limited series Crisis on Infinite Earths remains intact. However, some elements of the character's Pre-Crisis history may have been altered or removed for Post-Crisis New Earth continuity, and no longer apply.
- Brainwave once dated Jade.
- Brainwave is somewhat mentally unstable. Early in the development of his powers he had a tendency to create illusions subconsciously that could fool even himself. According to Doctor Mid-Nite, Brainwave has an abnormal mass of nerve fibers leading from his auditory cortex to a growth on the side of his inferior colliculus in his brain which he hypothesized is what drives him insane and gives him his telepathic abilities.
- 108 Appearances of Henry King, Jr. (New Earth)
- 18 Images featuring Henry King, Jr. (New Earth)
- Quotations by or about Henry King, Jr. (New Earth)
- Character Gallery: Henry King, Jr. (New Earth)
Justice Society of America member
Legion of Doom member