There, in the middle of the chaos, was Finn's father, Bill. The close-up had only lasted a second, before soldiers dragged him off . . . The computer screen froze on a picture of horses.
It's been a year since the computer sent Finn on a quest to Coralia. Now he finds he must re-enter The Ultimate Adventure to rescue his father. But how will he find out where Bill has been taken? He meets a girl, Nell, who seems to know, and she has her own reasons for joining Finn in an attempt to do the impossible: they must break into the seemingly impenetrable heart of Coldkeep Castle, and then get out again . . . alive.