Every Slavic river has them. The Rusalki — plural, because they almost always travel in groups — are the spirits of young women who died too soon and too wet: girls drowned by accident, by suicide, by murder, or simply by being unbaptised when the river took them. They live now in the deep pools and the slow bends of the Dnieper, the Vistula, the Volga, the Don, the Pripyat. From the first full moon of summer to the end of Rusalka Week in early June, they leave the water.
The description is consistent from Ukraine through to Russia and Poland. They are pale, beautiful, naked or wrapped in white linen, with long unbound hair the colour of river-weed that they have to keep wet or they weaken. They climb up into the birches and willows on the bank and sit there combing it, singing in voices that carry for miles across the water. A man who hears that song and goes to look does not, in most versions of the story, come home.
What the Rusalka does depends on the region — and on her mood. In the south, in Ukraine, she is often gentle, even sad: she wants company in the cold of the river, and the men she pulls under she pulls under almost tenderly. Further north, in Russia, she is closer to a vengeful ghost — she tickles her victims to death, drags them by the ankles, fills their lungs with weed. Either way, the rivers are full of them in May and June, and Slavic villages used to close the swimming holes for the whole of Rusalka Week, dress girls as Rusalki in mock funerals, and ritually 'see them off' back into the water at the end of the festival so the fields could be safely planted.
She belongs to a wider Slavic ecology of spirits — the Leshy who owns the forest, the Kikimora who haunts the corner of the kitchen, the Vodyanoy who rules the deeper river — and each one tells you something about how Slavic communities understood the wild. The Rusalka in particular carries an old, uncomfortable truth: that the unmarried girl who died young is a debt the village still owes. She is what happens when a life is cut off before its proper time. Folklore is rarely just folklore.
Wear the Rusalka and you wear the Slavic river at midsummer — the pale figure on the willow branch, the green hair drying in the moonlight, and the song you should not, on any account, walk down to the water to find.