1.Nf3 f6 2.Nd4 Nh6 3.e3 c6 4.Qh5+

Black can play 4...g6 5.Nb5 (or 5.Qc5 d6 6.Qb4 Ng4 7.Kd1 Nxh2 and black is better) 5...Ng4 6.f4 and white is better.