When David, Andrea, Mark, and Tammy go on a cruise together, David and Andrea unexpectedly rekindle their romance. Mark's preoccupation with reeling in a big fish to outcompete Steve DelVecchio leads to him catching a whale that jeopardizes the safety of the entire cruise. Meanwhile, Hank goes on a date with a mermaid that goes awry when she reveals her distaste for hot dogs.
Mark, in an attempt to bond with his stepson Darren, insists on teaching him how to throw a handmade boomerang that was gifted to Darren by his father. The two soon find themselves on a trek deep into the Jersey woods in search of it, where they encounter the Jersey Devil himself. Meanwhile, David is the recipient of a sex doll that he swears he didn't order, and is put through the wringer trying to return it.
When Tammy is upset that an elite country club only takes men, Mark joins it to supposedly change things from within. Meanwhile, Tammy's passion for the club infuriates the owner's wife, Ellen, and she invites Tammy to join an elite league of women dedicated to combating global, female issues. Meanwhile, Mark's entry into the club ruins the natural order, prompting the board to pursue the nuclear option and admit women.
Mark buys himself a Superbowl ring and leverages it to get special treatment at the Eagles game, only to wind up in Eagles jail for lying his way into becoming the new Eagles coach. Meanwhile, when Mark appoints Hank as the backup mascot, Hank has his own adventure with cutting-edge mascot technology.
Mark, trying to prove to Tammy that he can get babies to like him, writes a hit song that becomes the next Baby Shark. He enlists his family and neighbors to join his management team, putting these relationships to the test during his meteoric rise and humiliating fall. Meanwhile, David tries to capitalize in Mark's wake by resuscitating his old and out of touch climate change educational magic act.