Jack Barlowe is the primary antagonist of Fourth Wing, a cruel young man defined by a ruthless desire for power and a relentless ambition to undermine those he perceives as competition. He can’t stand Violet from the first moment he meets her; he makes his first death threat against her when they’re on the Parapet challenge and he’s sitting down to shove other cadets off. From the beginning, Jack positions himself as Violet’s primary adversary. He’s profoundly resentful of her, full of hostility and bitterness no matter how Violet behaves. This hatred intensifies after Tairn, the dragon whom Jack had set his sights on, totally ignores him and chooses to bond with Violet instead.   

Jack's character arc centers around a series of betrayals. He’s willing to abandon alliances and exploit others if it advances his goals, however large or small. In the brutal environment of the War College, Jack views his peers not as comrades but as either obstacles or tools. He’s not afraid to dispose of anyone who gets in his way, literally murdering multiple classmates in “accidents” on the sparring mat. When other cadets begin to publicly resent Violet for her rapid ascent to success and her two bonded dragons, Jack becomes the ringleader of a group who have her worst interests in mind. By the time the cadets reach the War Games, it’s clear to the reader that Jack’s weakness of character is rooted in a deep insecurity about being bested by someone he considers a small, weak girl. Rather than trying to make friends and allies, Jack believes that power and dominance are the only means to achieve respect. For Jack, vulnerability is a flaw. Unlike Violet, who relies on strategy and compassion to survive, Jack gravitates toward brute force. In this novel, Jack represents the destructive impact unchecked ambition and resentment can have on people raised to see others as disposable. His character is a thematic counterpoint to Violet’s; as she improves and grows, Jack worsens and withers inside.