When Ryan's father goes to investigate a scientific research facility based on an off-shore island, he finds himself stranded with a group of strangers. When nobody returns from the island, Ryan receives a cryptic message from his dad.
Josh dumps Ryan in the middle of the mysterious forbidden zone to pay him back for cutting off their communications. Shocked by his actions, the girls insist on rescuing him.
With their parents still not back, Ryan tries to enlist Natasha's help to retrieve the walkie talkie from Maggie. However, he still has a lot of making up to do before she will give him the time of day.
Natasha attempts to teach Josh how to read without the others finding out. Emma makes a startling discovery about her sister while searching for a food thief with Zuke.
Despite Em's shock over Lily's secret, the sisters find a way to deal with the situation during their parents' absence. Meanwhile, Jarrah challenges the boys to a fishing competition with amusing results.
Natasha realises her true feelings for Ryan, but has she left it too late to say anything? As it is Ryan's last day at base camp, Jarrah doubles her efforts to make an impression. Unfortunately, an accident is not what she had in mind.
Ryan attempts to leave for the island, even though he has no idea which way to go or what he will find when he gets there. Rob makes a break for it while Ryan seeks comfort.
Ryan and Jarrah risk everything and leave for the island. Meanwhile, at base camp the intruder draws nearer and Rob confesses to Natasha that he's not who he appears to be.
Stranded at the medical outpost on the quarantine island, Ryan and Jarrah repair their boat and decide to return home. Meanwhile, much to Lily's disgust, Josh and Rob initiate a hunt to track down the intruder.
In order to get closer to Rob and discover his secrets, Ryan betrays his friends. Meanwhile, Jarrah proves to Lily that she can trust her instincts, and Josh extends a hand of friendship to Gabe.
Ryan has a dangerous accident will collecting materials to build a raft. As his life hangs by a thread, Ryan and Natasha finally declare their feelings for each other.
When Rob destroys Schwartz's diary, Lily helps Gabe let go of the past and move on. Zuke stumbles upon the research lab belonging to Gabe's father and comes to realise that he has been wrong about Rob.
To everyone's shock, Jarrah refuses to be rescued and sacrifices her freedom in return for information about the island. Emma and Zuke scheme to get Rob to reveal the encoded diary to them.
When Zuke goes missing, Jarrah escapes from her prison to search for him, abandoning her plan to get the map. Ryan and Natasha suffer a setback while testing the raft but are rescued by Josh and Gabe.
Faced with the truth that both Rob and Ryan have been lying to her, Natasha has to decide between them. The boys try to convince Natasha that Rob cannot be trusted.
The kids force Rob to leave camp, but it comes back to haunt them when they discover he holds the key to Zuke's health. Gabe is invited to stay at camp, Elly plays miracle worker, and Rob has an unlikely defender.
The kids' plan to go to the island is thrown into disarray when a message is found from Mr. Taylor warning the kids not to come. After deciding to risk the voyage, the kids arrive at the island but discover only more questions.