In part one, when Tom meets another wizard called Jackson Hawke he can't resist dabbling in dangerous magic. Benny tries to warn him, to no avail, but all three lads are unaware of the Nekross getting closer and closer – and this time, alien Prince Varg is determined to make it personal.

In part two, Tom and Jackson take the fight to the Nekross, but their forbidden Grim Magic is taking its toll on Tom. Only Benny can help his best friend – but he's been enchanted. Tom's dad Michael and gran Ursula fight to reach Tom in time, but dawn is rising, and the final confrontation is about to begin . . .

When Gwen is snatched from Camelot without warning, Merlin knows there can be only one person responsible: Morgana. Arthur is determined to rescue his Queen, but it will not be easy, for she is locked in the Dark Tower, a place that haunts the dreams of men. Arthur and his Knights must embark on a quest like no other, battling through a landscape riddled with hidden dangers, perilous obstacles, and magical beings. As they near their goal, Merlin's sense of dread reaches breaking point. What twisted game is Morgana playing? And more importantly, just what is the final test that awaits them in the tower?

In part one, Lexi adopts human form and transports to Earth, with one aim – to capture Tom Clarke. But both are unaware that a greater enemy is watching – scheming billionaire Stephanie Gaunt is determined to prove the existence of magic, and nothing can stand in her way.

In part two, with Tom and Lexi held prisoner by Gaunt, the wizards and aliens must learn to work together, but is the alliance doomed to fail? As Benny faces the terror of the Brain Scrape, Gaunt's plans begin to escalate – with magic and Nekross technology combined, she can rule the world!

In part one, Tom's quiet Saturday at Benny's house becomes a thrilling fight for their lives when the vicious alien Grazlax hunts them down. The two boys must learn to fight together, combining Tom's magic with Benny's science, or the Nekross's savage pet will succeed – and devour them.

In part two, the Grazlax is out of control. But Tom has used up all of his magic, and Benny's scientific genius is useless against a creature from beyond the stars. It's a race against time for both humans and Nekross as the Grazlax menace grows – but will stopping the rampage leave any survivors at all?

In part one, when Tom meets another wizard called Jackson Hawke he can't resist dabbling in dangerous magic. Benny tries to warn him, to no avail, but all three lads are unaware of the Nekross getting closer and closer – and this time, alien Prince Varg is determined to make it personal.

In part two, Tom and Jackson take the fight to the Nekross, but their forbidden Grim Magic is taking its toll on Tom. Only Benny can help his best friend – but he's been enchanted. Tom's dad Michael and gran Ursula fight to reach Tom in time, but dawn is rising, and the final confrontation is about to begin . . .

In the inky depths of an ancient pool, three soothsayers cast a dark judgment upon the king of Camelot. But despite Merlin's warnings, headstrong Arthur refuses to take the words of the Disir seriously, and their fury rains down on Camelot. Only the greatest sacrifice can appease them, and with the kingdom in jeopardy is it one that Arthur is prepared to make? Faced with the king's uncertainty, Merlin has just one chance to save him from his destiny - but this decision comes at the highest price.

When Gwen is snatched from Camelot without warning, Merlin knows there can be only one person responsible: Morgana. Arthur is determined to rescue his Queen – but it's not going to be easy, for she is locked in the Dark Tower, a place that haunts the dreams of men. Arthur and his Knights must embark on a quest like no other, battling through a landscape riddled with hidden dangers, perilous obstacles, and magical beings. As they near their goal, Merlin's sense of dread reaches breaking point. What twisted game is Morgana playing? And more importantly, just what is the final test that awaits them in the tower?