Children's animation featuring Joe, who's given a mysterious, magical book for his birthday and has no idea it's a time-travelling device until it sends him and his friends, Sam and Fred, on a wild ride. Anna and Jodie are flung from a trebuchet and hurtling towards Castle Dunbar, Scotland, during a siege in 1338 by the Earl of Salisbury. When the kids meet Uncle Joe in the dungeon they realise much more is at stake.