Best friends-turned-business partners take on not only each other but roommates when they encounter a '50s diner-themed stack; siblings and a pair of cyclers confront a kids room-themed stack.

Two lovebirds battle it out against a mother-daughter duo on the supermarket stack; a married couple take on a tightknit pair of twins on the granny's attic stack.

A married couple takes on a father-son duo; Nigerian siblings work together to beat two epidemiologists.

A father-and-daughter duo fights to beat a pair of childhood friends; twin brothers take on a couple of best friends; the winners from each round face off for a chance to win the grand prize of $250,000.

Hosted by Janelle James, four teams of contestants compete in an epic battle against gravity and physics as they attempt to remove items from towering, themed stacks. In round one, siblings are ready to take down the competition when they go against a couple and take on the sports stack. In round two, a husband and wife who hope to win the prize money and take their children camping, take on family members ready to do what it takes as they confront the '50s diner stack. The winners from each round face off against the national parks stack to earn a shot at The Mega Stack for a chance to win the grand prize of $250,000.

Hosted by Janelle James, four teams of contestants compete in an epic battle against gravity and physics as they attempt to remove items from towering, themed stacks. In round one, a pair of best friends who are planning the girls' trip of their dreams tries to defeat two competitive brothers on the kids' room stack. In round two, a couple here to put their love to the test takes on a pair of musical theater classmates, who are used to performing under pressure, on the wedding stack. The winners from each round face off against the pirates' stack to earn a shot at The Mega Stack for a chance to win the grand prize of $250,000 on the season finale.