Crossword masochists: these 45 super-tough puzzles are for you. But beware—they're so hard, your brain may go up in flames! Every brilliantly executed crossword will test your skills with devilishly difficult clues and wickedly tricky themes. There are even explanations for the toughest clues in the back, along with the answer grids! If you enjoy the Friday and Saturday offerings from places like the New York Times, you'll love these! Solve with a pen … if you dare.