An assassin is going through a house, methodically killing the people. Got the man, the woman, the girl, and there was only the baby left -- obviously the easiest.
Except that the baby is not in his crib.
And when the baby toddles off up the hill and into the graveyard, a ghost takes an interest in him, and other ghosts appeal to her to take him in, and Silas (who is not a ghost but isn't alive, either) encourages the assassin to think of that the baby clearly went downhill instead. There's a dispute, but the Lady on the Grey arrive to tell them that the dead must be charitable, and so the baby gets a new name -- Nobody Owens, because his new parents are Owens, and since he looks like nobody else, they will name him after him -- and the Freedom of the Graveyard. There he grows up, playing with ghosts and getting an odd education, making a friend of a little girl but losing her when she moves off, talking with the witch buried in the unconsecrated ground, werewolves and the danse macabre when the flowers bloom in winter.
But the Jack-of-All-Trades, who sent the assassin, aren't done with him yet.