Four Moves

This is the position after black move 4. What were the moves?
The key insight here is that knight on b8 was initially on g8.
| 1. | Nf3 | d5 | 
| 2. | Ne5 | Nf6 | 
| 3. | Nc6 | Nd7 | 
| 4. | Nxb8 | Nxb8 | 

This is the position after black move 4. What were the moves?
The key insight here is that knight on b8 was initially on g8.
| 1. | Nf3 | d5 | 
| 2. | Ne5 | Nf6 | 
| 3. | Nc6 | Nd7 | 
| 4. | Nxb8 | Nxb8 |