I watched from the balcony, my hands gripping the railing until my knuckles burned. Below, Paxton and Carlota talked. Her actions looked like she was happy, and his posture was protective. Every instinct in me screamed to step down, to remind my stepbrother exactly whose she was.

But then I saw a glow, faint at first, spreading over her skin near Paxton. It pulsed with her heartbeat. This made me understand what was going on, even though the both of them were not looking at it yet. The ...