To enter the windowless basement that serves as the best new bookstore in Lockhart, you walk down a flight of stairs lined with a couple hundred Dracula masks and strings of garlic. While many bookshops favor natural light, this space embraces the darkness. Haunt Happy Books is full of antiques, skulls, a gold skeleton in a glass case, and thick, beautiful bookshelves stocked with only one genre: horror.I visited Haunt Happy with my five-year-old, who quickly grew nervous about the loud footsteps, scraping chairs, and mysterious thumps coming from the ceiling. (The appropriately spooky noises were in fact caused by restaurantgoers enjoying Loop & Lil’s Pizza, the tenant above.) In a moment of possibly misguided parenting, I said, “Don’t worry, it’s just monsters.” I caught…