Figure 3.3.2.5[Black to move]

Find the kernel of a discovery for Black. There are a few of them: Black’s knight on e6 masks the bishop on c8 and the vertical path of the queen on e7; his knight on f6 masks the queen’s diagonal path toward h4. Your first thought is to see if any of those discoveries has a good target at the end of it, and this leads you to the loose White knight on e5. Black will take it for free with his queen if he can find something violent enough for his knight to do as it jumps out of the way. Checks always are attractive for the purpose, but here none are available. So what else can the knight do? Examine its circle of moves, or consider whether White has any other loose pieces; either way you are led to Nc7, attacking the bishop on b5 as well as discovering an attack against White's knight.