Good one! May be you should post the whole game that caused this position to arise :)

Appears contrived.. with pieces in very peculiar positions; but an interesting puzzle, nevertheless.

why does the black knight need to take the rook? Maybe the queen takes it and gets out of danger

 ... QxR

Nxd6 mate

Everything seems to work.  I once had a pile of Russian chess magazines that had puzzles of a similar style to those you post.  All contrived mates in 2, first move is quiet (no queen sacs) with lots of combinations.  I got this one quickly as I took it more seriously than your last.  Are your puzzles Russian?