What began as petty revenge turned into a matter of pride and finally into pure obsession. Bruno Horgan was once at the top of his field, providing weapons and munitions the U.S. government. Unfortunately, his penchant for cutting corners lost him his contract when safety inspectors closed him down for using inferior materials. Instead, the contract went to his competitor, Stark Industries, owned by Tony Stark (a.k.a. Iron Man. During the dismantling of his factory, Horgan happened upon a malfunctioning radar device that projected a beam that melted iron materials. He perfected the device, incorporating it into a costume, and became the Melter. Immediately going on a rampage, sabotaging Stark’s factories, he was confronted by Iron Man and defeated.

The Melter was freed by Baron Zemo to help form the original Masters of Evil as a counterpart for the Avengers’ Iron Man. However, Zemo’s plan, to destroy the Avengers and hold New York in thrall, failed, and the Melter was beaten by Iron Man once again. He was freed again to join the Masters in an assault on the Avengers while Zemo fought Captain America in South America but again failed to defeat them. He next joined the Masters when the team was organized by the Crimson Cowl (secretly Ultron), and although they initially were successful, the Masters were betrayed by the Black Knight.

Prior to this last outing with the Masters of Evil, the Melter was among those villains summoned by Doctor Doom to crash the wedding of Reed Richards and the Susan Storm thanks to his powerful Emotion Charger device. Richards was able to use a device from Uatu The Watcher to send all villains away with no memory of the event. After this, the Melter re-designed his weapon in the form of a gun and boosted its power to affect all metals as well as other materials. He sought revenge on Iron Man but was again defeated.

After his career with the Masters of Evil, the Melter joined with Whiplash and Man-Bull in forming the Death Squad out of their mutual obsession to defeat Iron Man. They confronted him at a comic book convention but were quickly trounced. His obsession unabated and his weapon further updated, he tried another villain team-up, this time with Whiplash and the Blizzard, all three receiving financial support by Justin Hammer. They robbed a casino where Tony Stark was dating Bethany Cabe, but the couple foiled the villains, who were remanded to Ryker’s Island. Freed by Hammer’s associates, the Melter joined Hammer’s army of villains guarding his Mediterranean “house boat” base. When Iron Man was framed for murder by Hammer, Tony Stark allowed his armor to be impounded as malfunctioning and tracked Hammer to his headquarters. With a spare Iron Man suit, Stark defeated Hammer’s army, forcing Hammer to escape but imprisoning his agents.

While in jail, Bruno came up with new specifications for his melting ray with help from a fellow prisoner, a nuclear physicist who had been convicted for tax evasion. Designing it specifically for Iron Man’s latest armor, he spent no time tracking down Iron Man once released. Ironically, Iron Man was wearing an old suit of armor that remained unaffected by the Melter’s beam, and he was defeated once again.

Having been defeated physically time and again left the Melter felling defeated more and more emotionally. He hoped to earn a more fearsome reputation by killing the Thing, who at the time was hospitalized after his battle with the Champion. However, nearly two dozen other villains hoped to also kill or capture the Thing, and they were kept at bay by dozens of heroes, each doing what they could to help their staunch friend recover in peace.

Ever persistent in his obsession, the Melter returned to work on a yet more powerful version of his melting ray, but after completing it, he was shot by an assassin of the Scourge of the Underworld who was posing as the Melter’s assistant.