Noah and Luke Morelle arrive at World's End Castle and meet all their companions. Their mom (Amy Robbins) is immediately arrested and the twins are left in a state of panic.

Noah and Luke discover who has been watching them. It is their father who they thought was dead.

Stephanie tries to justify what she did to Noah and Luke. Gaia, AJ, and Slim try to banish the 'ghost'. Cat has a disturbing flashback.

Cat and Noah are caught by Lena and try to protest. The teenagers are allowed in the village for the first time.

Mackenzie and Skink scare Cat. Noah goes into Duncan's apartment to find a map and gets caught.

Noah and Cat connect and Adan Senior tries to spy on AJ. Gaia gets a nasty surprise.

Noah and Cat discover a hidden elevator. AJ has to explain to Mackenzie they aren't dating.

Noah and Cat try to find their way out. Lexy and Gaia clash as Gaia moves in with the winters. Luke is lost.

Luke has found a cave. Cat has another flashback and turns to Lexy for help.

Lexy has another flashback. Noah tries to discover why he doesn't have a birth certificate.

Slim is terrified after he sees his 'doppelganger'. Gaia Slim and AJ try to get rid of their ghost.

Lexy has strange memories of the SZ. AJ and Slim enlist Mackenzie and Skink to get rid of the Evil Gaia.

Somehow Gaia has escaped from the fire. Slim and AJ are punished by Lena.

Lexy and Cat find some of her mothers things in Duncan's room. Slim and AJ discover their 'twins' and Gaia's dad is puzzled with her behavior.

Gaia describes to the others what she saw in the SZ and Noah connects with Casey.

Cat tells Moira what is going on but then thinks she betrayed her. Noah tries to convince the others they can trust Casey.

Lexy and Cat sneak into the SZ. Lexy finds out some sad news.

Noah is shown a secret by Casey. Lexy and Cat nearly get caught in the SZ.

The teens try to work out whether Casey can be trusted. Casey tells Cat he has been her guardian.

Cat finds herself being assessed as part of the twins training missions. Caitlin discovers life outside the SZ.

The twins explain what they are doing and Casey is on the hunt for more Pictish Balls.

Cat discovers the Origin. Scared, Cat runs from the SZ. They try to find Caitlin to explain what has been going on. Gregor and Gaia connect and Caitlin gets a shock.

Noah, Cat, and Lexy discover something odd in Casey's room.

Noah, Cat, and Lexy are terrified by the picture they saw in his room.

Cat has disappeared and Slim and AJ tell the others what the discovered in the SZ. Gregor and Gaia continue to bond as they try to decode the SZ symbols.