"The Fourth-Dimensional Man!"
Thor returns to Avengers' Mansion with Hildegarde, bereft of the Lady Sif's company. His chagrin is vented on a startled and apologetic Jarvis.
Karl Sarron is revealed as the other-wordly Mercurio, the Fourth-Dimensional Man, who intends to steal the Thunder God's Asgardian energies to save his native world. It seems some villains start out with noble intentions.
Wielding searing heat in his left arm, and withering cold in his right, Mercurio proves to be more than even Thor can handle alone. Cue, the Warriors Three.