Complex sentence: Suddenly his ghost appears to Andy and explains Andy's werewolf condition and for Andy to become normal again he must eat the heart of the werewolf that bit him who he believes is Serafine.
Split into simpler sentences: Suddenly his ghost appears to Andy and explains Andy's werewolf condition. In order for Andy to become normal again he must eat the heart of the werewolf that bit him, whom he believes is Serafine.