The smell of old paper and cold coffee, left over from lunch, stagnated in the cup. The light from the desk lamp cast harsh shadows.

Cal leaned back in his chair, and the leather upholstery accepted his weight with a quiet creak. He ran his fingers over the bridge of his nose, trying to relieve the tension that had built up over the long hours. A face was frozen on the monitor. It was always a face. A micro-expression, lasting a mere forty milliseconds, stubbornly eluded a clear diagnosis. It was there—he knew he had seen it. A trace of deception, fear, or guilt, hidden in a wrinkle near the eye or a slight quiver at the corner of the lip.

He played the recording again. Rewound it. Again. The facial muscles don't lie; they scream the truth the brain is trying to suppress. This monotonous action was his form of meditation. The office silence was broken only by the whisper from the speakers.

He looked at his hands resting on the desk. The watch on his wrist impassively counted off the seconds that, a couple of hours ago, should have told him it was time to go home, but he was still there. Outside, the city was dark, with only street lamps illuminating the roads or the lit windows behind the curtains of buildings. Cal knew he should go home, but he couldn't leave until he understood exactly what the micro-expression on the screen in front of him meant.