He attacks Eva several times throughout the book. At the beginning, he assaults her by attacking the Sanctuary, where Eva evacuates under Muthr's instructions, leaving through the vent fan's shaft, while he attacks Muthr, who jumps into the gym pool. Eva, now hidden in a tree, witnesses the marauder leave from afar.
After she meets Rovender Kitt, Besteel finds Eva, captures her, and hangs her from a tree among other captured victims in a base camp. She and Rovender Kitt plan and execute a joint escape, freeing a water bear named Otto in the process, to help fly them to safety.
Later, the trio go to Lacus in hopes of ferrying to the royal city of Solas, where they may find clues about the human race. Besteel kidnaps her and flies her against her will to the city, to be embalmed and taxidermed on display in the Museum. Muthr and Rovender rescue her, but by the time they arrive, she has escaped and is planning to hotwire an ancient hovercar (nicknamed the Goldfish) and ride to the ruins of a great human city (which Zin, the curator, had informed her of, and which Eva will discover is New York City.)
When they arrive, Besteel confronts Eva for a final attack, who has brought reinforcements from Solas. If Eva doesn't give in, he threatens to murder her now close friend, Rovender. When Eva refuses, Besteel fires his boomrod at her, but Muthr leaps forward to protect her and dies shortly afterward. During Besteel's final moments, a group of sand-snipers kill Besteel and his reinforcements, dragging them underground.
In the battle for Wondla, Besteel is thought to have returned, but it is only a bird catcher called Redimus.
He is of a species called the Dorceans, and is covered with black-and-grey fur. He uses a sonic rifle, commonly called a "boomrod" throughout the book, a device that sends a charge of compressed sound out of the end.