This is an untitled poem that Osip Mandelstam wrote in March 1931:
After midnight the heart picks the locked silence
right out of your hands. Then it may remain
quiet, or it may raise the roof.
Like it or not, it’s the only one of its kind.
Like it or not, you may know it but you’ll never catch it,
so why shiver, now, like a thrown-out child?
After midnight the heart has its banquet,
gnawing on a silvery mouse.
From Osip Mandelstam, Selected Poems, trans. Clarence Brown and W.S. Merwin (NY: Atheneum, 1983). The sketch of Mandelstam is by Alexander Osmerkin.