When recent NYC-transplant Liz Brinkley and her husband are invited to an exclusive soiree by their neighbor, "lifestyle guru" Britta Harris-Che, Liz's immediate thought is hell no. Britta is insufferable, and Liz is wary to leave her young children with a barely-teenage babysitter. And yet she RSVPs anyway, trying to extend an olive branch to her withdrawing husband, who seems desperate to get in with the cliquey elite. They've barely made it through their first round of champagne when a "red alert" comes through their phones: strange atmospheric masses, reported to look like "glimmering clouds," have been spreading through major U.S. cities and killing anyone they touch. Authorities have one clear directive: Find shelter. Immediately. A collective panic seizes the dinner party; all the guests have children at home. In the mad dash to their cars, they see it: a shimmering net floating over the town. The street is littered with wrecked cars and dead bodies. Leaving now is not an option. Instead, the group launches into survival mode, grabbing supplies to take shelter in the hosts' wine cellar. As tensions and suspicions among the party guests near a boiling point, Liz becomes increasingly willing to do whatever it takes to get back to her children, but she soon realizes there may be others in the cellar even more desperate than she is...