Late at night in the White House, President Ronald Reagan awakens with a sudden painful sensation. As he takes another drink of water, we discover he is transforming into a human reptile….
All over Washington, the streets are in chaos as many citizens are morphing into reptiles, crashing cars and attacking the innocent. Viper’s three minions, Copperhead, Cobra, and Boomslang, fight their way through the deadly mob with Cobra finally learning what was in the canisters they emptied into the city’s water supply (last issue). They make it back to their craft to find The Captain (Steve Rogers) and Diamondback waiting for them As the two sides meet, Cobra tries to tell Diamond that he is really working undercover for Sidewinder to infiltrate Viper’s gang. He escapes through a torpedo tube and heads for the other Serpent Saucer parked nearby. There he encounters Nomad and D-Man with the captive Viper and Slither. Cobra fires a mini-acid bomb at the villainess but it is deflected by Nomad—but Viper is able to use it to burn through her cuffs. Nomad berates D-Man for allowing Cobra to get by him and heads off in pursuit. Viper frees herself and bites D-Man on the neck….
At the offices of the Commission on Superhuman Activities, the director learns that the water supply has been poisoned. He tries to alert the White House but can’t get through. Choosing to keep the Avengers out of this, he summons the new Captain America (John Walker) and Battlestar, who are stranded in Pennsylvania after their confrontation with the Resistants (again, last issue). The heroes are frustrated that they are being pulled off their assignment at the whim of the Commission….
With the captured Boomslang and Copperhead, The Captain and Diamondback discover the wounded D-Man. Diamond administers the anti-toxin and Cap tells her to stay behind while he goes after Viper. She broods about how she loves Cap but fears he will never trust her because of her criminal past…..
Meanwhile the anarchistic Viper is on a shooting rampage through the city, heading for the White House. Nomad, pursuing, is mobbed by reptile-people and overwhelmed, as the Cobra broods over his future, having betrayed both Sidewinder (he’s not really an undercover agent) and Viper. He slithers off. Viper, meanwhile, shoots her way into the Executive Mansion, pausing briefly to consider murdering the transformed Nancy Reagan. Locating the President, Viper gives him more water….
Back at the Serpent Saucer, the concerned Diamondback leaves the prisoners in charge of the barely conscious D-Man and, suiting up, heads out—and runs into Captain America. But it isn’t the one she knows. The new Cap orders her to surrender and gives chase. Meanwhile, Battle Star has entered the saucer and the delirious D-Man, thinking the new hero is a villain and wanting to redeem himself for his cowardice (in issue #340) attacks him. The two fight, with the super-slugging match moving out into the park. Battlestar manages to knock out his foe, as New Cap returns with the captive Diamond…..
The Captain heads through the chaotic streets toward Washington, dodging attacks by snake-men and arrives at the White House. Vaulting the fence, Cap enters the Executive Mansion and cautiously surveys the bodies of dead Secret Service men. While musing on the symbolism of the President and the White House (and wondering if Reagan approved his firing—or was even told about it in advance) and reminiscing about his first meeting with FDR, he reaches the Oval Office. Entering he finds Reagan has completely transformed into a snake-man and the President attacks him. Steve struggles against his foe while trying to appeal to his reason and his patriotism. He notices that, contrary to the habits of reptiles, Reagan is sweating, meaning he is trying to throw off the effects of the serum. Viper appears and denounces The Captain, America, and Western Civilization, gloating over its imminent destruction. The Secret Service arrives and she leaps through a window. As the President convulses and changes back to normal, Cap heads out in pursuit of the villainess. On the lawn he finds Cobra with the unconscious Viper in his arms. The serpent villain wants to make a deal; Cap refuses so Cobra turns Viper over to him anyway and slithers off into the shrubbery…..
The Commission meets and the Director makes the decision to apprehend The Captain, whom he recognizes as Steve Rogers the rogue former Captain America….
Epilogue: President Reagan addresses the nation, dismissing the Washington D.C. incident as the result of a hallucinogen being introduced into the water. He assures the public that the perpetrator is in custody and that he and the First Lady were never in danger. His teeth look strangely sharp, however….