On the one hand it’s kind of fascinating to think about the infinite possibilities of a person’s inner self. To think of all of their thoughts and emotions, not just the ones they share with you. To imagine all of the puzzle pieces to their personality in one box instead of just the pieces they put on the table. On the other hand it can be unsettling and even devastating to realize that someone you thought you knew completely has kept an entire side of themselves a secret. For Caitlin, this discovery comes after her best friend Ingrid commits suicide. Caitlin is stunned, heartbroken and desperate to understand.Caitlin’s entire world was Ingrid. Her hobbies, her idols and her goals were all built through their friendship. Without Ingrid, all of those things lose their foundation and leave Caitlin distrusting what they even meant to her in the first place. Ingrid leaves behind an illustrated journal for Caitlin and through its entries both Caitlin and the reader get a vivid introduction to both the Ingrid Caitlin knew and the Ingrid that kept herself hidden. Despite only living through Caitlin's memories and the journal entries, Ingrid has a strong book presence. It is very rough to read Ingrid's loss of hope. The more Caitlin discovers about Ingrid the more she questions what she actually knows about herself as well. By the end of the journal Caitlin has several new pieces to the puzzle of Ingrid and she must decide how to put them together and what to do with what she learns.I love when YA protagonists have serious hobbies and specific interests. When I was in high school I was always busy with some kind of wacky side project and I enjoy reading about other people's extracurricular interests. While Caitlin's photography was interesting to explore, I really liked her adventures in tree-house building.What is so great about Nina LaCour is that she allows her characters just to BE and the result is believable, fulfilling character interactions. Everyone from Caitlin's parents to Ingrid's crush to the new girl in school feel completely natural and it makes the emotional turmoil they all go through that much more poignant. Hold Still has a quiet and steady delivery that will settle into your heart piece by piece. Extended review originally posted on Young Adult Anonymous.