NEW YORK UNDER SEIGE! Infernal Hulk's ultimate target is revealed: Reed Richards' mysterious "IMMACULATE ENGINE," a supernatural machine in the Baxter Building that could destroy Hulk's army in a single blow! Can the Fantastic Four resist Infernal Hulk's corruptive power, use the machine and save Earth? Or will they be the next monstrous recruits in Hulk's INFERNAL AVENGERS?