Lucinda's Secret by Tony DiTerlizzi

In this enchanting continuation of the Spiderwick Chronicles, the Grace siblings—Jared, Simon, and Mallory—delve deeper into the magical mysteries surrounding their great-aunt Lucinda's past. As they seek answers about the fantastical creatures they've encountered, they visit Lucinda in a nursing home, where she reveals secrets about the hidden world of faeries and the dangers that lurk within. The siblings must navigate through a web of intrigue and deception, uncovering truths that challenge their understanding of reality and test their courage in the face of the unknown.