Near the beginning of the James Bond movie From Russia with Love, a chess match is depicted between the villainous Kronsteen, playing the White pieces, and one McAdams. The position is pictured here. Kronsteen plays 1. NxB, discovering check. McAdams replies Kh7. Meanwhile Kronsteen has been summoned away by a secret message from his bosses at SPECTRE; so now he plays 2. Qe4+—and McAdams resigns. Black’s best reply move would have been 2. …g7-g6, blocking the check, but this creates a fork for White with Rf7, winning Black’s queen for a rook. The position was based on one that arose between Boris Spassky and David Bronstein in Leningrad in 1960, though in the real game there were White pawns on c5 and d4. Bronstein resigned after Spassky played 2. Qe4+.
As a study in the rook fork the lesson of the position lies in three events that make Rf7+ possible: (a) Black’s king stepped forward from the eighth rank to the seventh, a classic site for rook forks because the rank can't be guarded by pawns and tends not to be patrolled (for defensive purposes) by rooks. (b) One of Black's pawns stepped forward from the seventh rank to the sixth, opening a line between the king and queen. And (c) White’s Qe4 cleared a path up the f-file for his rook. Each of these events is a type that can cause new tactics to become available: pins and skewers, as we shall see later, and forks, as we see here.
That’s all you need to see about the position for present purposes, but for the sake of completeness we can consider a couple of other variations. What, for example, is Black’s best reply to White’s initial 1. NxB? It’s 1. …Ne6, which blocks the check and pretty well puts out the tactical fire. Suppose, however, that in reply to 1. NxB Black plays 1. …Kh8. Now White can’t play Qe4 with check to clear the way for the rook fork. But White still has a wonderful move: Qc4, aligning the queen with the bishop on b3 and threatening to mate next move on g8. Black has no good reply. Kh7 doesn’t help at all. Qe6 blocks White’s queen but now allows White to play RxN+ instead. If Black recaptures RxR, his queen is left loose and White takes it. If Black doesn’t take the rook he soon will be mated. So Black’s best move after 1. NxB+, Kh8; 2. Qc4 is Nd7, clearing a path for the e8 rook to use to protect the mating square g8. But the knight’s move leaves g6 loose, and White uses it to play Ng6+, a fork that takes Black’s queen next turn.
Finally, suppose that after 1. NxB, Kh7; 2. Qe4+, Black declines to step his g-pawn forward and instead plays 2. …Ng6. This blocks the check without opening up the seventh rank for the rook fork White would like to play. But now Black is in bigger trouble, as White has 3. QxNg6, Kh8 (forced); 4. Nf7+ (always look for the next check in these situations). Now if 4. …Kg8, then 5. Ng5+ (discovering check by the bishop), and White is about to mate. Or if 4. …QxN, then 5. RxQ and White again will mate soon; Black can use his rook to throw some checks at White’s king, but this is just desperation. Other replies to White's 2. Qe4+ likewise end with Black getting mated. E.g., 2. …Kh8; 3. Rxf8+, RxR; 4. Ng6+, Kh7; 5. NxR++, Kh8; Qh7#.
Some of the ideas in these variations—as well as the idea of the discovered check that starts the sequence when White's knight steps away from f7—will be easier to understand after you have worked through the later parts of these lessons.