A shriek of terror left my mouth. Lashing out, I swung my container of oil into him. He toppled with a wooden clatter. The hat that had been atop the hatstand rolled away from me.

“Damn you, Victor,” I whispered. I had not noticed the hatstand during my earlier trip, being quite preoccupied. I picked up the hat and was hit with a shock of recognition even in the dark. I knew this hat.

It was Henry’s. I had purchased it for him, just before he left for Ingolstadt. I ran my fingers around the brim, feeling the velvet softness in contrast to the stiff shape of it. So Henry had found Victor when Victor was already living here. He had to have seen the madness taking hold. And still he had left.

Angry tears burned. He had left Victor, and he had left me. I did not know which betrayal hurt worse. Part of me, too, hated him for being able to decide to just leave. Some of us did not have that option, and never would.

I dropped the hat and poured some of the oil on it. I made a trail around the borders of the room until every last drop was emptied. Then I pushed Victor’s table into its path, as well as his wooden bed. I found more oil next to his stove and added that, soaking the bedsheets while I waited for the stove to heat up.

Finally, I went into the hall and draped the bedsheets on the ladder.

Back in the living quarters, I lit a match and dropped it onto Henry’s unfaithful hat. It burst into flames, which moved with liquid grace along the lines of oil on the floor. The heat was sudden and intense. I had done my job well. I backed out of the room, letting my eyes linger on Victor’s time here being erased.

No one would ever know what he had studied, how far down the path of his madness he had been allowed to stumble alone.

I lit the bedsheets and watched the fire climb the ladder to the trapdoor. Then I shut the front door behind me. No one would see the fire until it had overtaken the second floor. By then it would be too late to salvage anything. I backed up to the edge of the stone wall lining the steep riverbank and waited. I wanted to see the fire claim the horrors of his laboratory. I had to be sure.

It did not take long. Soon there was a glow, and then a brilliant, explosive burst that blew out the windows. I ducked as glass rained down around me. Whatever chemicals had soaked into the floor up there, they did not mix well with fire.