In this game, Black falters in the opening a little, but recovers in time to get to an endgame without too much damage. Just when it looks like we're in for one of those long rook endgames where both sides are trying to play offense and defense at the same time, Black drops his guard for a few moves and his king walks down a dark alley and never comes back.
A chessplayer has to be like a policeman and your opponent is the suspect. Even if you're just stopping him for a speeding ticket, you have to be on high alert at all times. Maybe you've given out hundreds of tickets and every driver driver said "yes, sir" and "no,officer" and went on their way, the next one might be armed and dangerous. In chess, you may have played a hundred rook endgames and they all revolved around capturing your opponent pawns and queening your own, but the next one might involve a mating net and you might be the one caught in it. Be alert, because it's never too late for mate.