If you want to solve this tactic yourself, scroll no further, the puzzle is there, scroll further for the answer with explanations and stuff.
Black (me) has just captured a pawn on d5. White notices that, should my Queen be on d5, a fork could potentially happen on e7. Then he finds,
28. Rxd5! Rxd5 29.Qxd5+! Qxd5 30.Ne7+
And now White is just winning. Remember, forks are dangerous, and Knights are the master forkers. So, remember to keep your heads up for tactics.