In Wolf King Season 1, Drew's journey reaches another turning point when he is imprisoned by Lucas, who has arrived in Brackenholme for a formal feast. Drew is the son of the late Wolf King and possesses some extraordinary powers. His trip to Brackenholme was full of adventure, with his people and family abandoning him, prompting him to flee to the Dyrewoods.
When Drew feels some physical discomfort, Tilly, his foster mother, realizes he's about to transform. When the rat lord attacks Tilly, Drew fully transforms into a wolf and fights the rat. However, the villagers misunderstand and accuse him of murdering his mother, while Tilly tells him to find Duke Bergan in Brackenholme. This is what happened in Brackenholme and how Drew ended up in prison.
Why was Drew imprisoned in Brackenholme in Wolf King Season 1?
Drew learns to survive by surrendering to his inner Wolf during his time in Dyrewoods. As a turn of events, Drew encounters Whitely and Master Hogan, who agree to take him to Brackenholme after he saves them from some enemies. Whitely, being Duke Bergen's daughter, helps him get into Brackenholme by being his confidante.
However, Prince Lucas, the son of the Lionlord, is in Brackenholme for a formal feast and betrothal. Along with him are Vankaskan the Wererat and Hector the Werebore. Prince Lucas asserts his authority over Drew and claims him as his prisoner. He further plans to take him to Highcliff and execute him. Drew doesn't react immediately. The Duke sees an opportunity, and, while not wanting him to be killed, he suggests to Lucas that Drew might be mute, without fully opposing him. The Duke doesn't reveal Drew's true identity but highlights how he would be worthless to the Prince.
Despite the torture, Drew refuses to utter a word in Wolf King season 1

On the way to Highcliff, Lucas orders Vankaskan to torture Drew to make him talk. However, despite the pain, Drew refuses to say a word. This leads them to declare him mute, which reinforces Bergan's words. Eventually, Drew breaks his silence only with Hector, who is treating his injuries caused by the torture. He speaks to Hector, who, being empathetic and knowledgeable, explains different types of Werelords to Drew, giving him both hope and context about his situation.
Later, during the show, their camp appears to be ambushed by Wyldermen. However, it is later revealed that Duke Bergen staged the attack to facilitate Drew's escape. The Duke gave Drew a cloak and his wolf-shed sword to help him leave the camp, along with Hector. There, Bergen reveals his true identity as the son of Werger, the late Wolf King.