Cassian brings Nesta to the House of Wind training ring instead of Windhaven, explaining that Mor has returned to Vallahan and Rhysand and Feyre are busy. Inwardly, Cassian realizes that Nesta has resisted training in the Illyrian camp because her pride cannot bear failing in front of hostile male warriors, so he chooses a private lesson to remove that barrier. When Nesta still hesitates, Cassian offers a magical bargain: if Nesta trains for one hour, Cassian will owe her one favor of any size she chooses.

Nesta accepts, and the bargain surges with unusual force through both of them. Cassian discovers that the magic has marked him with a new eight-pointed star tattoo on his spine, which means Nesta bears the same mark. The charged moment deepens when Nesta notices Cassian shirtless and studies his body, but both of them redirect that tension into the lesson.

Cassian begins with fundamentals rather than weapons, insisting that Nesta must first learn balance, posture, and control. He has Nesta remove her boots and work through simple but difficult exercises focused on her feet, toes, stance, and core alignment. Nesta feels foolish and frustrated by how badly she performs, but she completes the first hour and discovers that even basic movement requires more discipline than she expected.

Instead of stopping, Cassian extends the lesson into breathing work, showing Nesta how breath affects strength and precision. When Nesta times her exhale to a thrust, she feels the increase in power and begins to understand the connection between breath, balance, and movement. As the second hour continues, Nesta becomes exhausted, but the repetitive breathing and exercises clear the mental noise that usually torments her.

During the cooldown, Nesta asks Cassian whether he likes flying, then asks why Illyrians clip females' wings. Cassian explains that it is an old practice used to control women, that he and Rhysand made it illegal, and that Emerie was one of the females harmed while Amarantha ruled. Afterward, Cassian gives Nesta water, and Nesta says the extra hour was free; before she leaves for the library, Cassian apologizes for saying everyone hates her, and Nesta replies that she has never hated Cassian, leaving him stunned by the admission.