After Berkhart's working relationship with Osborn ended when the Green Goblin participated in a magical ritual that rendered him completely insane, Berkhart was then approached by Maguire Beck, the female cousin of Quentin Beck (the original Mysterio). Maguire convinced Berkhart to re-assume the Mysterio identity following her cousin's suicide and the "Mad Jack" costumed identity was retired. But when the two sought to eliminate Spider-Man, Daredevil, J. Jonah Jameson and several other mutual enemies, the two revived the "Mad Jack" persona, with Maguire using holograms and lifelike robotic versions of Mad Jack and Berkhart himself to serve as proxies for herself while she laid in secret. In the end, Maguire was caught and exposed though due to her usage of Berkhart androids but Daredevil and Spider-Man were left unsure as to whether or not Berkhart was truly involved. However Berkhart did ultimately escape with a Mysterio costume, in the confusion at the end.