Art Pengriffin & The Curse Of The Four

Arthur Pengriffin's a normal kid with normal problems - crushes, bullies, zits, a restless mother who's on another planet. When his band rips the school concert on the eve of his 14th birthday and a record producer parent wants to sign him, it's happy days. Until mom Egrainne announces they're leaving the Welsh town of Celidon to which they've only just moved. Egrainne finally tells Art her great secret - his father was the wizard Merlin and she is King Arthur's sister.
Merlin was killed by the Four Horsemen of the Apocalypse - hideous Angel of Death, battle-scarred W. A. R., snot-dripping Plague and skeletal Fest - for denying them his magic powers. The wily wizard had gifted them to Egrainne to hold for Art until the boy is 14. She fled Camelot with baby Art in a time machine and they hid in the 21st Century. Now the Horsemen have found them. They want Merlin's powers.
Time to go. Art thinks his mum has completely lost it, until he finds himself back in time with unsuspecting Megan, seeking a sword and a stone. Camelot's under siege and King Arthur imprisons them as Art realizes his mother loathes all magic. She wants the power to die in her so that Art will then stay a normal boy. But Art's not sure that's what he wants. His father's powers are a chance for Art to be a hero - and anyway, aren't they his destiny? But if the Four Horsemen get them, they'll use them to destroy the world.
Art needs to decide and fast - his 14th birthday is only hours away.