Missed Tactic 3

Well, a slight fabrication, since the actual position didn't occur, but it was one possibility that may have arisen.

A recent  game has been very level and threatens to continue as such from this position.

Black has just played Nxe5, winning a pawn.

The actual position Nxe5

White did, of course, play the very sensible Rc8+ in reply, which would eventually regain the pawn, but my mind wondered...

What if White decided on Nd4, to threaten the Rook ? Where could the Rook  retreat to ? 

Wrong thought to have, as Nd4 presents Black with a very nice tactic !

A possibility after Nd4

What should Black play ?

Highlight for solution [ The Rook doesn't need to retreat... 1...Rxf2 2. Kxf2 Nd3 forking king and Rook : Black is a pawn up either way  ]