Rigby and Eileen get called away to Don's black belt ceremony forcing Mordecai and Margaret to hang out alone - and Mordecai to confront his feelings for Margaret now that he and CJ are no longer together and Rigby convinced Mordecai to enjoy being single.
Two groundskeepers, Mordecai (a six-foot-tall blue jay) and Rigby (a hyperactive raccoon) are best friends who spend their days trying to entertain themselves by any means necessary, much to the displeasure of Benson (their boss, who is a gumball machine) and to the delight of Pops (an older, lollipop-headed gentleman).
Their everyday pursuits often lead to things spiraling out of control and into the surreal: they open portals to other dimensions, summon demons via an -80s arcade game and accidentally use choreographed dance moves to send co-workers to the moon.