Published in 2019, Ali Cross, by James Patterson, is the first in a series of mystery thrillers for middle-grade readers about a boy who follows in the footsteps of his famous father, Detective Alex Cross. Young Ali Cross searches for a school friend who has suddenly gone missing; he must juggle schoolwork and the search while coping with the stress of his father’s trial for assault.

Author Patterson has written or co-written nearly 300 books, including more than 80 novels for young readers. He holds the Guinness World Record for the most #1 bestsellers on the New York Times list. More than a dozen of his books have been adapted for the screen. A passionate believer in the value of reading, he has donated three million books to children and members of the armed forces and spends over two million dollars each year on reading programs in the US.

Ali Cross has a Lexile rating of 700L, suitable for late-elementary and middle-school readers. The eBook version of the original 2019 edition forms the basis for this study guide. While the book is primarily told through Ali’s perspective, the narrative sometimes shifts to his father’s, which is noted as Alex Cross in this guide.

Plot Summary

Middle-school student Ali Cross, son of the famous African American detective Dr. Alex Cross, worries because his best friend, Gabriel Qualls, has gone missing. At church on Christmas Eve with his family, he offers a prayer for the boy. Outside, reporters hurl questions at Detective Cross about his upcoming trial for assaulting witness Stanley Yang, who’s now in a coma. Ali angrily defends his father, who must hustle the family away before things escalate.

The Crosses—Alex, detective wife Bree, college son Damon, high-schooler Jannie, and middle-schooler Ali, along with Alex’s grandmother, Nana Mama—return to their Washington DC home to find it’s been robbed. Christmas gifts are ransacked, as is Alex and Bree’s bedroom upstairs. Their gun lockboxes are missing.

Despite these problems, Detective Cross and his best friend, Detective John Sampson, drive a large bag of gifts to the Yang house, leave it on the doorstep, ring the bell, and slip away.

Ali and his dad visit Detective Wendy Sutter, who’s in charge of Gabe’s case. She asks Ali several questions about his friend and assures him that nearly all missing persons cases get solved. Sutter and Cross warn Ali not to get involved but to let the police do their work.

Chafing at this lockout, Ali starts his own investigation. He sets up a bulletin board with a map, push pins, and ideas written on index cards. He visits Gabe’s house, but Mr. Qualls—an angry, tattooed guy just back from prison—refuses to let the boy search Gabe’s bedroom for clues. At home, Ali convinces his mother to locate traffic-cam videos of Gabe’s last known position. The videos show that Gabe’s backpack, normally fairly empty, was filled to capacity.

Gabe and Ali usually play an online video game, Outpost, but Gabe hasn’t signed on for days. Ali contacts team players Cedric, Ruby, and Mateo, and they try to break into Gabe’s Outpost bunker, but it’s booby-trapped.

Late one night, the Crosses’ doorbell rings, and the family finds a bag with some of their stolen things, including the parents’ guns and Ali’s new laptop. He wonders if the burglar might be a remorseful Gabe. Dr. Cross learns that a handful of fresh burglaries have occurred in the neighborhood. At one residence, the perpetrator broke in through a doggy door; this means the thief is probably a kid. Alex again thinks it might be Gabe.

At school, the principal calls an assembly to discuss Gabe’s disappearance. Ali’s perpetual enemy, student Kahlil Weyland, taunts Ali about his father. Furious, Ali breaks Kahlil’s nose and gets punched in return. The principal suspends Ali for four days, and Ali’s father grounds him. The boy’s mind continues to work overtime on the case.

One evening, Ali notices a clue from Gabe implanted on his new laptop. It leads him to the Outpost online video game and a late-night meeting with Gabe. Gabe is OK, but he asks Ali not to search for him or tell anyone they’ve spoken. Ali hears a scuffle between Gabe and another person, and the connection goes dead.

Ali thinks Mr. Qualls is somehow connected to Gabe’s disappearance. He sneaks onto his mom’s police laptop and obtains information about William Dante Qualls, who’s been in prison three times. He visits the Qualls’ house again: Mrs. Qualls lets him look at Gabe’s sparse bedroom. Gabe apparently took with him his PlayStation gaming equipment. Ali realizes Gabe’s parents and the police already know the kid ran away.

Dante Qualls comes home and throws Ali out. Late the next night, Detective Isaac Olayinka phones Alex to inform him that police have found Ali’s school ID card at a fresh burglary. Alex confronts Ali, who realizes that Qualls stole the ID from his jacket and used it to frame him. He unburdens his secrets to his father and the police. He then admits to Cedric, Ruby, and Mateo that he’s been holding out on them about his conversation with Gabe. Angry, they shun him.

The police find Mr. Qualls’s fingerprints on Ali’s ID card. Alex rides along as Olayinka and Sutter visit the Qualls’ house. Mr. Qualls injures Sutter and escapes, but Alex chases him down, knocks him out, and arrests him.

The burglaries continue in the Cross neighborhood. Ali searches near one crime scene and sees Gabe returning a bag of stolen goods to a nearby house. He follows Gabe to a storage unit where the boy and his older brother, Ramon, have been living among the burglary loot. Ramon locks Ali inside, and then leaves with Gabe to find a truck to move the goods to a new location.

Ali uses Gabe’s PlayStation console to send an SOS. Cedric sees it and alerts Dr. Cross, who rescues his son. Gabe is with him, and the boys reunite. Ramon gets caught trying to steal a truck. He and Mr. Qualls will do time, and Gabe can once again live safely with his mother.

Dr. Cross’s assault trial centers on whether he deliberately pushed Stanley Yang. Cross says it was Yang who pushed at him and then fell. The jury finds him not guilty. Cross tells the press that police brutality is a problem, but he’ll do his best to help by upholding high standards. Ali becomes more determined than ever to follow in his dad’s footsteps and become a detective.