The story is set in Ireland and it certainly sounds like a vampire or werewolf tale, but it isn't. How about a story involving the sidhe? The wee people or perhaps, wee person, play a role in this slightly creepy tale.
Bobby gets himself in one too many scrapes. He and his cousin are part of gang of thieves in Dublin. Bobby's mother decides the best way to keep Bobby out of trouble and to avoid the moneylenders she owes money to, is to move to the country. Bobby does not like the idea and once he gets a look at where they wind up, he tells his mother he's going back to Dublin.
The previous tenant of the cottage they are renting, simply left. No one knows where he went. Since on identification or money was found, it was assumed he just left. No one seems overly concerned. However, as Bobby's curiosity gets the better of him, he finds evidence to suggest that Lars never left. There are also some strange drawings and writings of Lars' that sound somewhat like the superstitious tales of fairies.
None of the main characters are likable. Bobby is a troubled teen who has no respect for his mother and shows it. His mother leaves much to be desired as a mother, but she was very young when she got pregnant and her family more or less deserted her. Dennis, Bobby's younger brother is to be pitied since both his mother and brother treat somewhat cruelly.
Creature of the Night is more a study in how Bobby begins to see the world in a different light and how he has to change in order to relate to this new world. The old tales and the gruesome discovery of Lars also make him wonder about the reality of the Tuatha de Danaan. It is interesting and the ending is not neatly tied up, but I see a more mature man with perhaps a chance at a future.