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.

Mark buys himself a Superbowl ring and leverages it to get special treatment at the Eagles game; Hank has an adventure with cutting-edge mascot technology.

Mark puts his piloting skills to the test.

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.

After feeling slighted by a Navy recruiter, Mark sets out to join an elite unit of the Marines, only to be thwarted by his inability to properly make a bed. David teams up with a Veteran, hoping to ghost write the next American Sniper and can no longer distinguish fantasy from reality as his subject reveals stories from his past that are stranger than fiction.

Mark accidentally murders Hank with a crossbow while hunting a deer.

Mark goes into business with Gary & Barry's Water Ice Shoppe, a Glantontown institution, when faced with being deprived of his favorite summer snack during their annual winter closure.