Oh no! Ben Grimm's been poisoned by MODOK (him again) and he's starting to mutate, gettin' even uglier than he already is. Weakened from his previous battle and the virus, he stumbles around the streets of New York, across the path of some street toughs who think they can make their rep if they take out a superhero. Unfortunately for them a) the Thing in any state is pretty damn tough, and b) that was Steve Rogers they just passed right there. Captain America comes to the Thing's aide (not that he really needs it) and helps him on his way to the FF HQ where Reed Richards and Giant Man are on hand to help out. What they discover is not only is Ben Grimm mutating, but he's also dying.
Giant Man consoles a raging Thing, he himself also dying. The two join forces to hunt down a cure from MODOK and AIM, meeting up with Cap, and and teleporting to an arctic fortress facing off against MODOK, the funky-suited AIM-guys and a giant 6-teeted Thing-like rock monster. Giant Man finds the cure that could save him and Ben both, but in the melee it's container is damaged, and naturally, he gives up his own salvation for Ben's well being before moping off to the tune of Christmas Time is Here.