I watched Hannah drink from the glass she believed was mine. She took a real sip, a committed one, because the plan required her to look relaxed and innocent, the sober, worried daughter beside her unpredictable father. I set my own glass down without drinking and folded my hands. Colin was watching me, waiting for whatever they’d expected to happen to me to start happening. His eyes kept flicking to my face, searching for the first sign of slurred words, of confusion, of a wealthy old man coming apart in a crowded room.

But it was Hannah’s face that began to change. A slow blink. A hand drifting to her temple. “I feel a little…” she started, then stopped, frowning at her own glass as if it had betrayed her. Colin leaned toward her, and I saw the exact instant he understood. His head snapped toward my untouched drink, then back to his wife, the color draining out of his confidence. “Something wrong?” I asked quietly, in the calm boardroom voice I’d used a thousand times. Hannah stared at me, and in her widening eyes I watched her realize that the two glasses had been switched, and that her own plan was now moving through her own bloodstream.