New arrival, Scott, settles in to life at Mt. Horizon, while his new group, the Cliffhangers, make their way back from an eventful 10-day quest in the woods.

Peter's old flame, Sophie, and ex-wife, Chloe, both show up for a visit. Juliette makes a play for Scott. Shelby fights her demons as the Cliffhangers help search for a lost girl.

Peter faces his estranged dad and his troubled past life in New York City to try and save Mount Horizon from foreclosure. Augie spirals over upcoming school placement tests.

Peter drags the Cliffhangers into the X-Challenge Race when he makes a bet against the Lawrence Hastings Prep School coach. Scott refuses to be a team player.

Juliette deals with her demons after falling into a cavern with a Native American skeleton.

Hannah's departure and Kat's impending graduation spark old emotions and rebellion. The Cliffhangers take care of eggs for a class project. Sophie returns from Africa.