Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A masterful thriller

This book made me anxious - but that's a compliment. I had time to read this only in small late-night portions, and my sleep suffered for a week. Magnuson portrays beautifully the internal conflicts of a man who stumbles onto a fortune, but can't let anyone know. The pacing is excellent, the dilemma gripping. Grab it for the beach this summer!