My phone beeped. I frowned and looked at the screen. Shit. The battery was at 14 percent. I was shaking and terrified and exhilarated and I couldn’t think clearly, but I’d be damned if I stayed in this place without a light to guide me out.

I decided that I better make it quick.

With trembling hands, I flipped off the flashlight and opened my camera app, turned on the flash, and started taking pictures. It was the only logical thing I could think to do at the moment, given I’d just found something which, truly, could be worthy of international news. “London Tourist Solves 200-Year Old Murder Mystery,” the headline might read, “Then Returns Home to Begin Marriage Counseling and Start New Career.” I shook my head; if there was ever a time to remain rational, it was now. Besides, I’d solved nothing.

I snapped as many pictures as I could, each time the room bursting alive under the glare of the bright white flash. As I took the first few pictures, the flash provided a rapid, fraction-of-a-second view of the room: there was a hearth, I thought, at one corner, and a single mug lay on its side underneath the table. But after the first few shots, the camera flash left white, floating dots in my vision; the effect disoriented me, and soon I could hardly keep myself standing upright.

Nine percent. Vowing to leave when the battery hit 3 percent, I considered how to best use the remaining battery life. I looked again to my right and snapped a picture of the counter—the flash helped me confirm that it was books, not boxes, that I saw a moment ago—and then I opened the largest book, which was lying flat on the work surface. Some of the words within appeared to be handwritten, but I couldn’t be sure. In the black cover of absolute darkness, I opened the book to a dozen random pages, taking pictures of each one. I might as well have been blindfolded, because I had no idea what I was taking photos of. Would the words even be in English?

Within the book, the pages of parchment were thin as tissue and I handled them as delicately as I could, cursing when the corner of one page fell away completely. I flipped to the back of the book and took a few more pictures, then I closed it, pushed it aside and grabbed another book. I opened the cover of this one, pressed the shutter button on my phone’s camera, and—dammit. Three percent.