The catastrophic tidal wave from Ultimatum #1 has struck Manhattan.
New York City is in ruins.

Amid the destruction:

Dr. Franklin Storm is killed during the flood.

Sue Storm is gravely injured and lapses into a deep, critical coma.

Reed Richards is missing, having disappeared during the chaos.

Chaos spreads across the city as survivors struggle to escape the devastation.

Ben Grimm is overwhelmed and nearly helpless — with Reed missing, Sue unconscious, and the city collapsing around him, he has no one else to turn to.

Ben remembers there are three people on Earth who might have the scientific expertise to save Sue:

1. Reed Richards — missing
2. Susan Storm — incapacitated
3. Dr. Harvey Elder — the Mole Man

With no other options, Ben heads underground into the ruined lower levels of New York to find the Mole Man.

Inside the subterranean tunnels:

Elder reveals he already knows about the tidal wave and its consequences.

Ben pleads for help saving Sue.

Mole Man agrees — but at a steep and unknown cost.

Meanwhile, the larger Ultimatum crisis continues to unfold across the Ultimate Universe.

This issue takes place after Ultimatum #1 and is officially labeled as one of the first crossover chapters.