Chess Opening Theory/1. e4/1...c6/2. d4/2...d5/3. Nc3/3...dxe4/4. Nxe4/4...Nd7/5. Qe2

5.Qe2?!
This is an unusual looking move, but it creates a subtle mate threat. Black can fall into it very easily in amateur play, and so this move is recommended. Black can get mated in one move if he makes an error.

If black plays correctly, it is easier for him to equalize. Black can get mated on move 5.