Eight months after the sudden loss of his astronaut mom, Alex undergoes rigorous entrance testing to attend the same leadership high school she did.

When the Eagles and Ravens start getting too friendly, the headmaster sends them on a grueling two-day hike devised to reignite their competitive fire

For their first challenge, the Eagles and Ravens compete to solve a riddle. To be accepted by his team, Alex distances himself from his older sister.

The Eagles pressure Alex to help them get revenge against the Ravens. FBI agents look for a weapon lost near campus and suspect a student took it.

A remarkable gift from Ryan boosts the Ravens' flagging spirits. Becca smothers Leo with attention. Brooke makes an impulsive, ill-timed decision.

The fallout from the hike reverberates inside and outside the school, leading to hard questions -- and a difficult decision.

The shadowy enemy puts a sinister plan in motion. Later, Sophie investigates questionable news while Daniel debates making a confession.

Brooke scrambles to keep a secret from Alex during an upheaval at the Greenhouse. Sophie's past choices threaten her current status at the school.

Members of the Eagles and Ravens team up on a risky mission to find a valuable chunk of magnetite. A disheartened Brooke looks to make a fresh start.

Trusted with personal information, Becca and Daniel each battle their true emotions. A schedule change poses a serious problem for a shadowy enemy.

While the Eagles and Ravens compete in a capture-the-flag challenge, Enzo receives a mysterious offer that's too lucrative for him to question.

Hayley learns who Leo's surprise visitor is. Emma faces consequences for her phone call to NASA. Jealous Daniel's temper explodes at the school dance.

As a sinister plot targeting the school unfolds, Hayley embraces her new lifestyle, annoying Leo, while Brooke argues with Alex about her brother.

Hayley's determination to get to the bottom of an annoying beeping noise unwittingly sets a deadly chain of events into motion.

As the Eagles and the Ravens examine evidence from an attack, a suspicious text from Leo leads them all to a shocking discovery.

Leo's setback creates tension between Hayley and Daniel. Meanwhile, an FBI investigation results in several major revelations.

As Hayley, Daniel and Leo edge closer to learning the truth behind the mystery virus, their real feelings about each other finally come out.

Brooke spots boyfriend Daniel doing something suspicious on the beach. Jackie gets to know Max's sweet side when he helps her with an assignment.

Flashbacks reveal a discovery that teenage Ryan made at the Greenhouse and an order given shortly before the Athena launch. Brooke is led into a trap.

When Aspen's jealousy gets the better of her, Leo tells her they need to talk. Judy and Marcus trigger a test quake and get unexpected results.

After an explosion rocks the school, one student hopes for a rescue while another one faces a threat from a mysterious virus.

As Hayley considers a risky way to save her classmate, the Eagles and the Ravens have a theory about the mystery virus.

Time is ticking as the shadowy figure makes a frightening ultimatum. Can the Eagles and the Ravens intervene in time to save the world?

During a quiz game, know-it-all Aspen grates on Hayley's nerves and Brooke suffers a strange lapse in memory. Max misses Emma and tries calling her.

Under the sea, Hayley experiences something that changes how she thinks about her mom. Believing the world is ending, Parker blurts out a confession.