When a malfunction occurs aboard the luxury space cruise ship Avenue 5, it’s up to engineer Billie McEvoy to warn Captain Ryan Clark, Avenue 5 owner Herman Judd and his right-hand-woman Iris Kimura that the incident may have a cataclysmic knock-on effect. As Rav Mulcair manages the situation from mission control back on Earth, Matt Spencer, the head of customer relations, tries his best to calm frayed nerves on board, and persistent passenger Karen Kelly discovers the crew may know more than they’re letting on.