After allowing invited dignitaries to leave, Dr. Doom tells the Avengers that two of the three Dooms in Avengers HQ are Doombots and that he himself has a bomb that he will activate if the heroes do not cooperate. Doom proposes an exchange of information – the secret of Doom’s infiltration of the HQ in return for the Avengers’ knowledge of inter-dimensional travel so that Doom may rescue his mother from another dimension. Captain America, Sandman and Vision battle the two Dooms in the Avengers’ sub-sub-basement and expose them both as Doombots. Vision solves the riddle of the Doombots’ ingress into the building. Realizing that Doom wouldn’t jeopardize his mother’s rescue by risking own life, Rage attacks the third Doom and exposes him as a robot too. The real Doom, in a limousine across the street, deactivates the bomb and drives away when he realizes that only the missing Thor could tell him how to traverse dimensions.