Visualize 1
Game
d4 Nf6 2. Nd2 e5 3. dxe5 Ng4 4. h3 Ne3 {white resigns, why?} 0-1
Board
Answer
Take the knight and Qh5 is forced mate, if you dont?
Taken from:
Chernev's 1000 Best Short Games: #1
Gibaud v Lazard