“It’s not her. It might not be anything. I’ll tell you in a minute. Wish me luck!”

“What in the world?” she said again, and laughed. Now she was curious. She saluted me with her teacup. “Off you go and hurry up! Good luck!”

I was not sure what I’d do if Nancy Campbell discovered me taking her fireplace apart, the day after I arrived in her house. What was the worst that could happen—might she fire me with no pay? I knew how desperate she was for someone to look after Jane. I could talk my way out of this.

I went back to Room Four, wedged the steel rod into the fireplace, and pulled. The panel came off easily, falling into the tiled hearth with a crash. I caught my breath, but no one seemed to hear.

I peered inside the hole I’d made in the wall of the Limehouse.

In the back of the fireplace was an old deep-set stone hearth that went right into the full thickness of the wall. The gas line came up through a pipe in the floor and ran behind the grate to connect to the new fire. It wasn’t at all disturbed by the panel being out. In the dark, sitting in the two-hundred-and-fifty-year-old hearth, was Felix Baer’s wooden case.

At first I was confused. I was sure I’d seen him carry it out of the house and put it in Ellen’s van yesterday morning. How could it be here behind the fireplace in Room Four?

I tried to remember what I’d seen, and realized I’d seen nothing. He’d used the gramophone as a decoy, and by some wizardly sleight of hand he made us think he’d put his own case in the Tilly ready to fly back to Norway with him. It was dark, and nobody checked in the back of the van to see if he’d put anything there or not, and he’d made sure Ellen and I were standing on the side of the plane where we couldn’t see him unloading before he took off again.

So clever. And so desperate! What exactly was this thing he’d taken such risks to deliver and leave here?

There was a small cardboard box in front of the case, not much bigger than my fist. I reached in and grabbed the box and the case, and then fit the iron panel back in place as fast as I could. It was easy to take apart and put back together, because Felix Baer had done the hard work of prying the panel loose in the first place. He must have broken it free of its fixture.

I closed up Room Four behind me and went back to Jane with Felix Baer’s wooden box.