Percival is a young boy who lives alone with his grandfather, Varghese, above the clouds on a mountaintop called God's Finger. On Percival's sixteenth birthday, a Holy Knight named Ironside arrives on a flying boat in hunt of Varghese, his former comrade whom he suspects is one of the Four Knights of the Apocalypse, a group of warriors prophesied to bring ruin to Ironside's liege, Arthur Pendragon. Ironside magically inflicts large gashes on the pair and leaves them for dead, but only Varghese is fatally wounded, while Percival mysteriously survives and heals from his injuries. Before dying, Varghese reveals Ironside to be Percival's father and urges Percival to find him, though Percival hesitates to leave for days until he finds travel garments made by Varghese as a birthday present. Donning Varghese's cloak and helmet, Percival climbs down God's Finger to the land of Britannia, where he encounters a red fox.