“Hey, Tsarushka!” he called.

Silence except for the low gurgle of the river below and the rustling of creatures moving unseen through the underbrush.

Vanya swore, hurrying to my side to slip the rifle free from the leather scabbard mounted across his saddle. By the time he undid the scabbard’s buckle, I had already taken my own musket and powder horn in hand.

As we headed deeper into the forest, the ground turned marshy, water puddling beneath our feet. Here and there, I spotted humanlike footprints in the loose black soil—not the tiptoed tread of a mavka, but heavy feet webbed at the toes.

I swallowed hard, my mouth suddenly dry.

“Seen anything like this?” Vanya asked, nodding toward the footprints.

“Back in the wilds. But I’ve never seen the creature they belonged to.” I left the rest unsaid—that aside from its footprints, the only omens of the creature’s existence had been the relics of its insatiable hunger. Disemboweled deer and rabbits torn apart, and once the mangled half of a fisherman floating in marshy shallows, the bruises of fingers around his throat and forearms.

“You think it could be a rusalka?” Vanya asked.

I shook my head. “They always stay by rivers, never swamps or ponds. And I’ve never seen one walk on dry land before.”

Still, I supposed there were always exceptions. In the wealth of taxonomy journals I had recovered from the trenches, I had read of rare instances of men returning as rusalki and women as vodyanye; sailor boys dragging themselves ashore to the shock of observers, with their hair running red down their backs and the new buds of breasts rising on their chests. A mavka with the face of a son, or a vodyanoy with the face of a daughter, and some returning as neither one sex nor the other. Perhaps this was no different.

“Mikhail!” Vanya called again, but the only answer was the rustling of the branches and then, faintly, the splash of unsettled water.

I had used my musket so many times through the years, it took me but twenty seconds to load and prime it. Vanya followed suit, jacking a round into his rifle’s chamber. Edging deeper into the underbrush, now up to our ankles in the marsh, we scoured the algae-streaked water for any sign of disturbance.

“Just like a noble to wander from the path,” Vanya muttered. “As if monsters have any respect for royalty.”

Despite his scathing words, I caught an edge of fear in his voice. His jaw worked silently as he turned away.

“I hope this swamp doesn’t get much deeper,” he said under his breath.

“Afraid you’ll drown?” The joke came out weaker than I intended, and he shot me a look.

“Yeah, actually, I am.” Vanya turned his gaze back ahead, restlessly fingering the rifle’s barrel. “I can’t swim.”

“You can’t swim,” I repeated, befuddled.

“Every time I go in the water, I sink like a rock.” He laughed dryly. “So much for being half rusalka, huh?”