The "shadow plague" is striking young and old throughout the world with severe amnesia, dementia, and eventual death, and no one knows the cause or the cure. Annie O'Rourke, a ninety-five-year-old retired nurse who runs a soup kitchen for the homeless in Lemon City, California, believes environmental degradation is the culprit. Development and pollution have devastated the Santa Ana River watershed, and Annie is convinced that if she purifies the river, she will cure Southern California's plague victims and stimulate worldwide healing.
With Whiskey Ed, Library Lady, the General, Roderigo, Skulford Elephant, and Perry - all soup kitchen regulars with special skills and powers - eco-warrior Annie forms the Magnificent Seven. Embarking on a campaign of inspired environmental monkey-wrenching, the Magnificent Seven attack a waste disposal plant, a cannery, and an oil refinery, inciting a media frenzy.
When Annie discovers a cure for the shadow plague that includes immersion in the Santa Ana River, she must try to convince authorities to conduct an emergency cleanup. Amidst negotiations, a twenty-five-day flood leaves its marks on Southern California. After the flood recedes, powerful interests seize the land and accuse the Magnificent Seven of terrorism. The group must plan its next move.