The Square Root of Murder (Professor Sophie Knowles)

for the more-loyal-than-me crafters and their instructor. I arranged a plate of number-shaped sugar cookies that a flunking commuter student had baked for me. The cookies were doing double duty as bribe offerings, it seemed. It hadn’t worked for the student, who flunked anyway, but there was no law that said I couldn’t give the treats another try. In a gesture toward good health, I poured out a bowl of baby carrots, and in a fit of overly cautious behavior, I tossed a bag of hickory-smoked almonds into the garbage, convinced that they had a bitter smell.
    I wrote a note to Ariana telling her that my house and fridge were hers and, by the way, I’d just ordered a new book on how to make beaded napkin rings and would make her a sample set by Labor Day. Bribes, bribes, bribes. Promises, promises.
    I stuffed a “best of” puzzle book in my tote and headed out to meet Rachel.
     
     
    There were pluses and minuses to living in a town that was only twenty-five miles from Buzzards Bay, the north end of Cape Cod. One drawback was that there was no good route to avoid traffic on a Saturday morning in July. It was marginally better that I was heading away from the Cape, on highway 495, and not toward it. Henley Airfield was on the northwestern edge of town, the opposite direction from hot spots like Old Silver Beach in Falmouth and the quaint shops of Provincetown at the tip of the Cape.
    Traveling in my direction were vacationers leaving the Cape, but with four lanes, the traffic was somewhat bearable. The common wisdom was that these drivers, having had to check out of their time-shares by eleven on Saturday, were the worst, since they were not happy to be heading back to their daily work lives. Having been cut off three times since leaving home, I believed it.
    An ambulance sailed by me, sirens blaring. I’d trained myself to think positive thoughts about emergency vehicles on the road: help is on the way. Since Bruce, however, my first thought was: too slow; instead of driving you should have taken a helicopter.
    As a mathematician, I tended to see everything in terms of logic diagrams and spreadsheets. I’d been mentally setting up a chart, even though it had been less than twenty-four hours since I’d learned of Keith’s murder and Rachel’s plight. I had nothing written yet, but I used the driving time to edit my lists anyway. I’d gone through possible suspects, alibis, motives, and access to the murder weapon. I’d started with everyone who attended the party, and added a few stray faculty members, plus the dean, all of whom I knew to have been at odds with Keith over one thing or another.
    The mental lists were too long now, and I was having trouble driving and concentrating.
    Screeeeech.
    I jammed on my brakes, luckily not slamming into an SUV in front of me. Some states had a hands-free law—no cell phones for the driver without a Bluetooth. I needed a mind-free law—no thoughts of anything other than the rules of the road.
    I needed to put off my diagramming task and switch to a different form of multitasking. Once I was on a back road to the airfield, I hit the Bluetooth device on the visor of my car and called Detective Archibald McConnell.
    I wasn’t looking forward to the call or the interview. My discomfort didn’t make sense. Thinking rationally, I should be jumping at the chance to talk to the Henley PD. The more information I had from them, the better my chances of figuring out something that would clear Rachel unequivocally. So why was I resenting an interview with Archie? Ever since I realized that Virgil was not joking when he’d implied that I was a suspect like every other Franklin Hall resident, I’d felt uneasy.
    Maybe just because, in general, cops were intimidating. I was a big fan of those whose daily jobs required putting themselves in potentially dangerous situations, just to protect and serve me and my loved ones. Bruce and the entire MAstar crew were in that number. Still, how many times had I been tooling along the turnpike at only one or two mph above the speed limit, and tapped my brakes when I saw a two-toned blue state trooper vehicle up ahead?
    I could only imagine how much worse it must be for the guilty.
    My Bluetooth speaker came alive. “Henley PD. McConnell here.”
    I gripped the steering wheel. “Yes, this is Sophie Knowles. Virgil asked me to call you?” But by the way, my inflection said, I can’t imagine why.
    “Yeah, hi, Sophie. I think we met at some