Free Killer Sudoku by Kaye Morgan Page A

the room. Will Singleton’s digital monstrosity had been replaced by what would normally be a wall clock showing the time as 6:20.
    A volunteer conducted Liza into the room and led her to an aisle seat. As Liza looked around, she didn’t see any particularly familiar faces. That was good. She’d feared Charley Ormond might persuade Will to create an all-star room to make her camerawork easier.
    Something else registered—a good number of seats stood empty, which didn’t seem likely given that the competition was supposed to start in minutes. Apparently some of the participants, having gotten one stiff taste of Singleton sudoku, had decided not to suffer through another.
    Liza took her seat and checked the two pencils and pens waiting for her. She grinned. I guess they decided there wouldn’t be any goody bags this time around.
    One of the tournament volunteers stood in the front of the room and rehashed the rules. Then she distributed the puzzles in their sealed envelopes. By the time she was finished, the clock up front had almost reached the magic moment.
    When the second hand indicated half-past six on the dot, the woman called out, “Please begin.”
    Liza grabbed a pencil, opened the envelope, removed the puzzle, and immediately began filling in candidates. Given the complexity of the last puzzle, trying out simpler techniques would simply waste time.
    As soon as she had all the possibilities listed, Liza began the work of thinning them down. She used the interaction between subgrids to prune some 3s out of one column. Then she spotted a naked pair—two spaces in the same row that had the same two candidates. That meant one space had to hold the 1 and the other the 5, and all other examples of those digits in the row could be eliminated.
    That was the easy stuff. Liza kept cycling through her dozen most dependable solving techniques, rising in complexity. She traced two X-wings, logical chains making a rectangular path across the grid work and establishing two pairs of possible answers for four spaces. One allowed her to remove three extraneous 7s. The other didn’t eliminate anything.
    Involved in tracing the possible logic of a swordfish chain, Liza suddenly became aware of movement behind her—how she couldn’t say. The room was so quiet, she could hear the ticking from the clock up front.
    Liza looked up to see the young volunteer seated behind the front table just like a test proctor for a final exam. She wasn’t the source of the movement. It had to be a camera crew.
    I must have really been off in sudoku land if I didn’t hear the door open, Liza thought. The camera people had to be making great efforts to keep quiet. She resisted the instinctive response of turning to look at them—and the childish urge to hide her work from the glass and metal eye peeking over her shoulder. She just set her jaw and continued working.
    Was Will sitting with Charley in another room, looking at the feed from this camera and doing professional commentary?
    “See, Charley, she’s wasting time tracing a useless swordfish when she could eliminate a whole slew of sixes with this swordfish over here.”
    Gritting her teeth still harder, Liza derailed that train of thought. No second-guessing. She continued on until she again lost herself in the flow of numbers.
    She’d not heard the reappearance of the crew as she wrestled through several more swordfish, then reached the tipping point where more and more spaces got filled through simpler techniques. They were definitely behind her as she checked over her solution.
    Of course, they’d want to be in close for the kill.
    Okay. It worked out. Liza raised her hand, causing a bit of a stir among the other contestants. The volunteer came to take her puzzle and then nodded almost imperceptibly toward the door in the rear.
    It took Liza a moment to take the hint. Well, duh. Why should I sit around here? Especially when the camera people probably want to film my exit?
    Liza rose,