The Square Root of Murder (Professor Sophie Knowles)

class in the fall.”
    “I saw the flyer.”
    “Don’t sound so skeptical.”
    “Me?” I asked, all innocent.
    “Do you have any samples of the dean’s handwriting?”
    “Probably somewhere.”
    “I could look at them.”
    She held up the binder and fanned the pages at me, but I couldn’t read the writing by the dim light of the blue and green lava lamp. “These are my notes. I’ve already picked up more tips from this lecture I heard last week. Did you know you can tell a lot about a person even from the pressure of the pen on the paper?”
    “What if you’re using a pen that doesn’t write dark, or is running out of ink?”
    Ariana ignored me as she usually did when I brought a rational explanation into a conversation.
    “A slant to the right means emotionally outgoing and to the left means you’re restrained.”
    “What if the person is left-handed? Bruce is a lefty and his writing is slanted way to the left. I wouldn’t call him restrained. Would you?”
    “If the person writes very small it means a great ability to concentrate on small details.”
    I’d long admired my friend’s ability to slide right past a question or a comment and continue with her own agenda. I couldn’t do it. Maybe it was an occupational hazard from my years of working with proofs and logic, where the requirement was to have each statement follow from the one before, without skipping a single step, even a simple one.
    “Do tell,” I said. She would anyway.
    “You should see a sample of Albert Einstein’s handwriting. It’s tiny, tiny, but very, very accurate as far as the shape of the letters. Charles Darwin’s, on the other hand, is all over the place, with a very wavy baseline and wide spacing between the words.”
    I couldn’t resist. “Well, Einstein could have had a limited amount of paper and Darwin might have been on the ocean on his ‘Beagle’ when he was writing.”
    “You’re no fun.”
    “I hope you don’t still have the letters I wrote to you while we were in college,” I said.
    My friend gave me a wicked smile. “I marked them up with a red pencil. I put notes in the margin—”
    Ariana might as well have hit me with her red binder. Why did it take me this long to see it?
    “That’s it!”
    I slammed the palms of my hand together, creating one loud clap. “That’s what I’ve been trying to figure out. It’s been bothering me forever, but I didn’t know why. Now I do: if they were really Rachel’s yellow pages that were strewn around the crime scene, they wouldn’t have red pencil marks.”
    “Should I be following this?” Ariana asked.
    “Keith never looked at students’ yellow sheets. All the girls have told me that. He simply would not read drafts. They were beneath him. So there was no way Rachel would have given him a copy on the yellow paper, therefore, no way he would have read it, and therefore, no way he would have marked it up in red.” I opened my palms to signal how clearly each step followed from the one before. The conclusion wasn’t quite up to snuff mathematically, but it was obvious to me. “The yellow pages were marked up and planted by the killer.”
    “This is good, right?”
    I hugged my friend. “This is very, very good. I need to call the cops.”
     
     
    Ariana was elated that she’d given me the key to deciphering a major piece of evidence at the Franklin Hall crime scene. She cleared her desk for me—no small task since neither neatness nor doing paperwork received a lot of her attention on a regular basis. She put piles of folders on top of other piles of folders and left me alone with my cell, a pad of paper, and a pen. I intended to take my handwritten notes immediately out of her presence as soon as I was finished.
    I mentally rolled up the imaginary sleeves of my sleeveless knit top. Not a problem; I’d taught a whole course in imaginary numbers last year.
    I called Virgil. He, and not Archie, answered on the second ring. So far, so good.
    “I don’t want to disturb you if you’re still talking to Rachel,” I said.
    Virgil chuckled. “Your friend is doing fine. We just needed to get a few more things straight.”
    “She’s still there?” I wondered if anyone but a lawyer or blood relative was entitled to that information.
    “She’ll be here for a while.”
    “Like, all night?” I heard my voice rise and my language lapse into studentese.
    “Hard to say.”
    “Did you pick up—?”
    “Invite in for questioning, you