When a malfunction occurs aboard the luxury space cruise ship Avenue 5, it's up to engineer Billie McEvoy to warn Capt. Ryan Clark, owner Herman Judd and his right-hand woman Iris Kimura that the incident may have a cataclysmic knock-on effect.

After five long months, the passengers of Avenue 5 eagerly await their impending return to Earth­­ while behind the scenes, Ryan and the crew struggle to find a way to reveal the much longer timeline of their journey home. Later, a disgraced Karen comes to blows with a newly famous Frank.

The crew turns to a Judd-designed ranking algorithm to deal with their latest threat. As Ryan’s rating mysteriously tanks, Billie searches for her more worthy counterpart, and Judd attempts to make amends with an estranged Iris.