Shannon is worried about the wolves and their safety; now people know they exist, they may be hunted. She plans to inform the Department for Environment, Food, and Rural Affairs so it can protect the wolves but first needs proof that the wolves exist and she knows how to get it - Kyle's wolfbait.

Meanwhile, Rhydian is being tracked in the woods by his brother Bryn, who has just found out from his mother that he exists. Rhydian takes him to his foster parents' house, but it's the first time Bryn has ever been in a human house and he knocks over lots of things by mistake, meaning they have to run away.

Shannon and Tom find themselves in terrible danger in the woods as they are tracking a feral Ceri and Bryn with wolfbait. They are driven wild by the smell, and Maddy has to escape from her house to try to rescue her friends. She gets there just in time, but to save them she has to transform in front of them. The secret is out and life will never be the same again. What will become of Maddy, Rhydian, and her family?

Three years on from the end of Series 4, Arthur has never felt stronger, with Queen Guinevere and the Knights of the Round Table at his side.

Camelot basks in the halcyon days of a new golden age. But even as she flowers, so the dark seeds of her destruction are being sown, for in the frozen wastelands of the north, men are disappearing without trace.

In search of answers, King Arthur and his Knights must undertake a dangerous mission to the unknown. As the sun sets on the icy plains, Merlin finds himself locked in a battle unlike any he has fought before - a battle with fate itself.

Ancient prophecies of Mordred weigh heavy on Merlin, for not even he can sway Arthur from his chosen path.

As dawn breaks across the icy tundra, Merlin and Arthur are close to exhaustion. With each tortured step, the fortress of Ismere looms ever nearer and Merlin's fear intensifies. What game is Mordred playing? And what powerful secrets are Morgana and the druid Ruadan searching for amongst its twisted catacombs?

It seems like this time not even Merlin can stop Arthur from walking right into the lion's den. For in this bleak and transient wilderness, only one thing is certain: the great trial for Albion has finally begun.

Rhydian starts dabbling with his Eolas powers in school and showing off to his friends. Maddy can't understand how he is doing it, as the tricks go far beyond his wolfblood senses and speed. He shares the secret with Maddy, who runs off joyously using her new skills without hearing the downside he shouts after her: you can't cross electrical fields while using it or it causes immense pain – something she finds out the hard way.

When Rhydian takes Maddy home her mum is furious at what she's been doing, but her dad is far more understanding and later Maddy finds him trying to access Eolas himself. Emma ends up forbidding a defiant Maddy from seeing Rhydian outside school, but when she storms off using her new powers once again she lands herself in trouble and needs her parents' help.

Once again it is the day of the full moon and Maddy and Rhydian aren't looking forward to a night in the den. They trick her parents and lock them in, running off to the woods to change under the full moon.

Meanwhile, Shannon has been trying to forget about the beast by throwing herself into other interests, but when handsome beast-hunter Kyle Weathers arrives in town looking for her she is soon back on side.

Out in the woods, Maddy and Rhydian are drawn by Kyle's bait and he shoots them with a tranquilliser gun, captures them, and plans to sell them. Shannon realises too late that Kyle isn't her soul mate, and she and Tom race after him to try to rescue the wolves.