In this excerpt from "The House of Hades," Percy notices Annabeth’s demeanor, suspecting she is devising a plan. He describes her subtle expressions, indicating that she has a particular look when she’s scheming, which prompts him to directly question her about it. Annabeth, however, denies having such a look, seemingly deflecting Percy's teasing while maintaining a sense of mystery surrounding her intentions.

The interaction takes a humorous turn when Annabeth asks Percy if he has a pen, to which Percy responds incredulously, suggesting that she is joking. This leads to a moment of reflection for Percy as he realizes that, despite having his sword, Riptide, he has never actually tried to use it as a writing instrument. This adds to the lighthearted tone of their banter, revealing both their personalities and their camaraderie.