Demonata #1, The: Lord Loss

Grubbs Grady is a typical Irish teenager until he returns home to find his family slaughtered — and the demon responsible, Lord Loss, still in the house. Institutionalized and disbelieved, Grubbs is finally pulled out by his eccentric uncle Dervish, who reveals what the massacre really meant: demons are real, and the Grady bloodline carries an ancient curse.

That curse is now surfacing in someone close to Grubbs, and the only way to stop it is a wager with Lord Loss himself — a supernatural chess match where Grubbs must win three games out of five while his uncle holds off the demon's monstrous familiars. Losing does not mean losing a game.

The first book in Darren Shan's Demonata series, Lord Loss is told in first-person, present tense, and was singled out by a Telegraph reviewer for one of the grisliest family-murder openings in children's literature — establishing the series as genuinely dark horror rather than lighthearted fantasy, building steadily from psychological trauma to a tense, high-stakes climax.