Biological warfare traps four teen-aged backpackers in the Adirondacks: Doug, a wilderness expert whose temper has already caused serious trouble; Loop, his best friend; caustic Orin, crippled in a motorcycle wreck; and his sister, Ernie, the love interest for both other boys, whose devotion to Orin is sorely tested by his bitterness. Together, they try to reach Doug's grandfather, a local environmentalist. Although set in the near future (the President is a woman), 60's anachronisms include pot-smoking folksinger Ed--who provides music therapy for Orin, listens to Doug's woes, and helps Loop and Ernie sneak off for a night together. Baird examines the implications of the War Powers Act, the general lawlessness that can result from breakdowns in communications and the legal system, and (cursorily) the causes of the biological warfare disaster--concluding that no one will be spared. But although the social commentary and the dynamics of a group under pressure may fascinate readers (as they did in Sleator's House of Stairs), Baird's story is problematic in its assumption that laying down nuclear weapons will merely lead to another form of extermination that the Soviets will initiate, even though the US will retaliate in kind; and while the survival of other species offers a modicum of hope, the outlook here is chillingly bleak.