Owen receives a warning from homeless man Martin that the dam is about to collapse. At first, he does not believe it, but anonymous texts, storm forecasts, and old engineering posts push him to prepare. He leads his roommate Caleb to the eighteenth-floor rooftop, and the flood soon swallows the city. As hunger, injuries, insiders, raiders, and delayed rescue push the survivors to the edge, they build a fragile order of mutual support. In the end, Owen leads a mission to recover medicine and supplies, uses a rooftop SOS to bring rescue, and reveals how one hot meal changed everyone’s fate.
