At a summer camp with a focus on ornithology, loner Bee is constantly guarding her secret: She has super-sensitive hearing. She’s developed a method of closing auditory “gates” that allows her to filter out some of a constant barrage of sounds. Bee soon befriends Zippy, a feisty Jewish girl with her own super-sensory power, the ability to see clearly in the dark. Along with peevish fellow camper Felicity, Bee and Zippy decide to use their abilities to aid them in investigating a mystery involving a cabin of older girls, the Hawks, whose flashlight batteries are dead every morning. Despite appearing exhausted, the Hawks are never seen leaving their beds at night. Entering the Hawks’ cabin after dark, Bee, Zippy, and Felicity (all white) discover a hidden trapdoor leading to a long, dark, underground tunnel; Bee can hear the Hawks’ voices in the distance. Summoning their courage, the younger girls follow. Their discovery—that the girls are meeting up with boys to dance—is not what it initially seems, and soon the girls are entangled in a ghost story involving not only the Hawks but also the elderly founder of the camp and the boy she secretly dated decades earlier. Moderately paced with a masterful balance of plot and character development, this mystery novel has it all: excellent writing, hair-raising scenes, prickly-yet-heartwarming friendship, and a cozy, retro vibe.