Ghost Society. Spellwood Academy, #4

After the events of Hollowfell, Spellwood's security has been doubled, and Kyra Solschild is in a haze of depression from the loss of Lucien. To make matters worse, Lucien's best friend, Tryst, made Lucien a promise to look after Kyra. She's not happy about his sudden shadowing of her everywhere, and neither is Tryst. Meanwhile, all of Spellwood is prepping for the Wintertide Ball, the biggest celebration of the school year.
The campus is covered in snow. Music and the smell of cinnamon float through the air. And some people are keeping secrets. Kyra has almost begun to adjust to her new normal when she uncovers a shocking secret about where Lucien has gone...