Twelve-year-old Charlie O'Reilly is the only person who remembers Liam, his nine-year-old brother, who suddenly vanished a year ago on Charlie's eleventh birthday. His parents and classmates think he's mentally ill, and the only person who believes him is his best friend Ana Finch, even though she doesn't remember Liam either. Charlie despairs of ever seeing Liam again, until he discovers that Jonathon, the assistant baseball coach, has knowledge that could help him. In the meantime, he starts to experience vivid dreams in which he is Kieran, a boy traveling from Ireland to America in the 1840s.
The Missing Piece of Charlie O'Reilly contains examples of:
- Abandoned Area: Charlie and Ana spend much of their time exploring the deserted industrial area by the shoreline, full of crumbling buildings and even a boarded-up mine. The only place they avoid is the burned-out New York Asylum for Orphaned Children, where dozens of kids died 170 years ago.
- Annoying Younger Sibling: Charlie is a neat freak who keeps his comics alphabetized. Liam used to mess up his comics to annoy him.
- The Atoner: Brona went to the Asylum to take Kieran home with her and was dragged out by three men. In her struggles, she knocked over a lantern, starting the fire that burned down the Asylum. She sees the work she does - taking children from their lives and keeping them in a place with no strong feelings and no consequences - as a way of making up for all the pain she caused, and of preventing the children from suffering the pain of a normal existence.
- Be Careful What You Wish For: In the weeks leading up to Liam's disappearance, Charlie begged his parents to let him have his own room for his eleventh birthday. They refused. The night before his birthday, Liam accidentally ripped the cover of one of Charlie's comic books, and the two got into a fight. That night, Charlie silently wished Liam would go away and leave the room to Charlie, and he did.
- Catapult Nightmare: Charlie bolts upright crying after a dream in which a police officer takes Kieran away from his mother on the grounds that she's an unfit guardian who will raise him to be a criminal and sends him to live in the Asylum.
- Daddy Didn't Show: Charlie's dad misses his twelfth birthday because of a business trip.
- Dumbwaiter Ride: The Asylum had a dumbwaiter. Charlie's final memory as Kieran is of being trapped in the burning asylum with his mother Brona. The two tried to escape by riding in the dumbwaiter to a lower floor, only to find themselves trapped in the wine cellar. They didn't know about the secret door, so Kieran died when the roof fell on him.
- Five-Finger Discount: Cody tried to shoplift a bottle of expensive perfume because he couldn't afford a birthday present for his grandma. When the security guard caught him, he tried to run but dropped the bottle. Instead of a present, his grandma got a $440 fine.
- Gayngst: Michael is gay. He never came out to his parents because he knows they'd reject him. His most shameful memory is of his crush smiling at him. Once he escapes from the Asylum, he does come out to his parents, who react as he expected, forcing him to live with his aunt for a while. Now he's back with his parents, who eventually adjusted.
- House Fire: Kieran's family makes the decision to move to America after their hovel burns down, killing his little sister Nora.
- The Illegible: All O'Reillys have the same hard-to-read handwriting. When Charlie finds a scrawled note left in his backpack, he realizes it must be from Liam. It's actually from Jonathon.
- It's All My Fault: Liam, Jonathon, and all the other vanished kids asked Brona to erase their existences to undo something they'd done. Sometimes it's something genuinely horrible, like Jonathon burning his brother while playing with firecrackers. Sometimes it's something trivial, like Liam cheating off Charlie's homework, or something that wasn't actually their fault, like a girl who blames herself for her grandfather's death because she was arguing with him when he had a heart attack.
- Kick the Dog: The police officer who takes Kieran from his mother stops to kick a pig that was following him down the road.
- Lost Pet Grievance: Shayla is a little girl who accidentally left the front door open once. The dog, Piper, escaped and was hit by a car. She had Brona erase her out of guilt.
- Man on Fire: When Jonathon was fifteen, he and his younger brother who turns out to have been Charlie were playing with firecrackers when their dad showed up, furious. Jonathon dropped the Roman candle he was holding, which went off, turning his brother into a fireball. His dad tackled his brother and rolled with him to put out the flames while Jonathon ran to call 911. In the burn unit, they had to keep him unconscious for over a week because of the pain. The night before Charlie was supposed to come home from the hospital, Jonathon lay in bed begging for a way to undo the accident. Brona granted his wish.
- Minor Living Alone: Jonathon escaped from the Asylum into a world where no one remembers him, so he lied about his age and started working for a lawn care company that pays in cash and doesn't ask questions. His boss rents him a one-room apartment over his garage. Jonathon will be eighteen soon, so he won't have to lie anymore.
- My Parents Are Dead: When Cody tells Ana and Charlie about his attempted shoplifting, Ana says, "Your parents must have freaked." Cody says, "I don't have parents." He explains that he never knew his dad, and that his mom was a petty criminal who died in a drunk driving accident when he was six.
- Orphanage of Fear: Before the Asylum burned down, it was a miserable, filthy place where the kids were barely fed enough to stay alive.
- The Password Is Always "Swordfish": Charlie spends hours trying to guess the six-letter password to Brona's wine cellar by punching in various words that have some relevance to her past. Eventually he realizes that the password is the first initials of her and her five lost family members. When he punches them in from oldest to youngest, the lock falls open.
- Ret-Gone: Brona erases the kids' existences and any effects they had on other people and takes them to live in the burned-out Asylum, which only they can see as an intact building.
- Secret Room: Behind a shelf in the Asylum's wine cellar is a door leading to a section of the salt mines, now blocked off by cave-ins. The original owners installed the door so they could smuggle wine. Brona puts children who turn eighteen into an eternal sleep in which they never age, and keeps them lying on cots in the mine. There are people there dating back to the 1840s.
- Security Blanket: When Charlie was seven, his dad told him he was too old for his baby blanket. Charlie shoved it between his bed and the wall. He still touches it to comfort himself, but no one else knows it's there.
- Signature Scent: Charlie's mom smells like Aveda shampoo, Dove soap, and grapefruit.
- Tantrum Throwing: When Jonathon realizes that forgiveness won't actually bring the Asylum kids back into existence like he thought, meaning he, Ana, and Charlie are stuck there forever, he throws the king from a chess set across the room so hard it breaks in half. The Asylum's magic quickly repairs it.
- Tears of Joy: Charlie cries when he is finally reunited with Liam.
- Why Couldn't You Be Different?:
- Neha was the daughter of two world-class athletes, but she turned out slow and uncoordinated. Her parents refused to accept that she just didn't like sports and were angry at her for supposedly not trying her best. When she didn't make the high school track team, she didn't want to deal with their disappointment, so she had Brona take her away.
- Madison's mom and stepdad were disappointed in her because she got all D's and F's in school, due to dyslexia that no one realized she had until she came to the Asylum.
- Wish Upon a Shooting Star: Since Liam's disappearance, Charlie has wished on wishbones, pennies, and fountains, trying to bring him back.
- Your Favorite: Brona serves Charlie cinnamon rolls, his favorite food, which his mom used to make before her depression got severe. Unfortunately, although they smell delicious, they're as flavorless as all the other food in the Asylum.
