One of Tony Stark’s competitors, Bruno Horgan, loses a big job because Stark showed a prospective client that Horgan was using inferior parts. Later, Horgan develops a ray that melts iron and he decides to go after Stark. He melts a munitions shipment after knocking Stark out and then he takes his mayhem and destruction into one of Stark’s plants. Iron Man loses some armor on his arm but he gets the Melter to flee after he cracks a hot water pipe and gets it to spray on the Melter, forcing him to flee rather then getting scalded.
Later, Stark gets some heat from a congressman because his production has fallen off. They think the Melter is a figment of his imagination or just a way for him to explain his company’s failings. The Melter eventually strikes again but this time, Stark is ready because he built a new suit of armor out of aluminum, which is immune to the Melter’s ray. The Melter does escape into a sewer although it’s unclear whether he survived the plunge or not.