Harbinger walks into the Monitor's sanctum as he continues testing young Alexander Luthor. Luthor is aging at an accelerated rate, and is now the physical age of an adolescent boy. The Monitor discovers he is composed of both positive matter and antimatter, and believes that this composite life form may hold the key towards stopping the Crisis. Harbinger, still under the influence of a dark, mysterious entity, leaves the Monitor's satellite and reports to her new master.

On Earth-One in the 30th century, the Flash races through the streets desperately attempting to halt a series of natural disasters. He sees a wave of pure antimatter spreading outwards in the distance. He vibrates his molecules at super-speed sending himself backwards through time.

In the 20th century, the antimatter wave has reached Earth-One and it slowly begins to dissolve everything in its path. The Teen Titans team up with the Outsiders to save as many citizens of New York as possible. Batman and Superman arrive as well to lend a hand. Suddenly Batman sees the Flash appear before his eyes. The Flash screams in terror and quickly disappears.

In outer space, Brainiac's brain-ship surveys the progress of the antimatter wave. He logically deduces that in order to preserve his own life, he must help to save the Multiverse. Brainiac flies off to find his old partner, Lex Luthor.

Meanwhile, Blue Beetle, Doctor Polaris and Geo-Force arrive in Markovia in the spring of 1944. Markovia is currently under Nazi occupation and the Nazis attempt to secure the Monitor’s energy tower. The American military forces known as Easy Company, the Losers and the Haunted Tank are present as well. While the heroes engage the Nazis, they must also contend with a horde of Demon-Shadows. The Demon Shadows succeed in killing several war time soldiers including Johnny Cloud, Captain Storm, Gunner and Sarge.

On Earth-AD, Superman, Dawnstar, Solovar and Kamandi stand by helplessly as they watch the sky turn the color of blood and lightning storms erupt all around them. Solovar, finally succumbs to his recent injuries and dies in Kamandi's arms.

Meanwhile, Cyborg, Green Lantern, Psimon and Firebrand materialize in the town of Coyote, Texas in the year 1879. They meet up with several Southwestern heroes including, Nighthawk, Scalphunter, Bat Lash, Johnny Thunder and Jonah Hex. The two disparate groups join forces and locate another one of the Monitor’s towers.

However, the destructive wave of antimatter that the Monitor warned off strikes the Earth at all time periods simultaneously. While the other heroes fight against more Demon-Shadows, Nighthawk is consumed by the antimatter wave.

Across time in the 30th century, the Legion of Super-Heroes shares a similar tragedy. While saving innocent civilians in England, Kid Psycho falls prey to the white energy wall.

Back on the Monitor's satellite, Harbinger returns. Consumed by the influence of her new master, she releases a blast of energy at the Monitor.