The security guard listened to my deductions and admitted he was indeed late this morning, with panic written all over his face. He didn’t think too much about his colleague, Mr. Wang’s absence since he assumed he had already left.

I scanned the room with Cave Vision and noticed a few clues. Outside the security room, I found a glove in the grass beside the road, and the matching one slightly further away.

We followed this lead until we reached a construction site.

At the sight of a large group of policemen, the man in charge came forth and asked what had happened. "A man wearing a security uniform might have entered the site last night,” I explained. “Was there anyone on duty here?"

The foreman was just about to call someone when anxious shouts suddenly interrupted him. "There’s a man in the mixer!" exclaimed one of the workers.

We walked over,...