Shadow of the Colosseum. Survival through the Ages, #4

Captured and sold to a brutal gladiator school, 15-year-old Robert must survive the deadly spectacles of the Roman Empire using his modern hunting instincts rather than raw strength. Because he is smaller than the seasoned warriors, he relies on his "mechanic's brain" to rig the arena environment and outsmart his opponents with physics and clever traps. The stakes escalate when the Empire realizes his unique talent for tracking and outmaneuvering predators, forcing him into the arena to face exotic, terrifying beasts brought from the farthest edges of the world.
These lethal encounters serve as a gritty callback to the prehistoric monsters Robert faced in his past, but this time he is performing for a bloodthirsty crowd. While navigating the treacherous politics of the gladiator pits, he must locate the flickering "glitch" hidden within the Colosseum's labyrinthine tunnels to make his escape. After a final, explosive showdown against a legendary predator, Robert dives through the anomaly and wakes up safely in his own bed in 2020.