Parallel

for my laptop. If Caitlin and I stopped being friends last October, then my screensaver picture of Caitlin, Ty, and me at graduation doesn’t exist anymore. My screen lights up. The graduation photo is gone.
    I click on the camera icon and quickly scroll through the rest of last year’s photos.
    After October, Caitlin’s not in any of them. Not a single one.
    I have to talk to her. Now.
    I sprint from Vanderbilt to Silliman in my socks, colliding with four different sets of passersby and nearly taking out a man on a bike. When I get to Caitlin’s door, I bang on it. Her roommate, Muriel, opens it, still half-asleep.
    “Abby?”
    “You know who I am!”
    “Of course I know who you are,” Muriel replies, looking at me like I have three heads. “But Caitlin’s not here. She’s at the lab.”
    “Whose lab? Dr. Mann’s?”
    Muriel nods, rubbing her eyes sleepily.
    Grinning like a madwoman, I throw my arms around her. “Thank you!” Out of the corner of my eye I see the keys to Muriel’s Civic, hanging on a hook by the door. The next train doesn’t leave for an hour. “Can I borrow your car?”
    Muriel shrugs. “Sure. It’s in the lot on Sachem.”
    “Thank you!” I throw my arms around her again.
    “Wait, you’re not high, are you?” Muriel eyes me suspiciously.
    “No!” I grab the keys from the hook before she can change her mind. “I’ll bring it back this afternoon!” I call as I sprint down the stairs.
    I make excellent time. Since it’s a Saturday, I ignore the PERMIT HOLDERS ONLY signs in the parking lot at Olin Observatory and park next to the only other car in the lot, a bright-yellow Smart car with Connecticut plates and an EXPECT THE UNEXPECTED window sticker. At least I know I’m in the right place.
    According to the directory by the main entrance, Dr. Mann’s office is on the sixth floor. Once I’m up there, it’s not hard to find. His door is the only one covered in newspaper headlines about last year’s earthquake. Next to this door there’s another one, marked LAB . The knob turns easily in my hand.
    I push open the heavy metal door and step inside. On the far wall, an oversized digital clock declares the time down to the millisecond. Beside it, there is a giant magnetic calendar with a movable red X on today’s date. Dr. Mann is standing in front of a floor-to-ceiling chalkboard that runs the length of the eastern wall, studying a string of equations, his shirtsleeves rolled up to the elbow. Caitlin is nowhere around.
    Quietly I turn to go, hoping to slip out without being noticed. But the door clangs shut before I can catch it.
    “Good morning, Ms. Barnes!” Dr. Mann calls.
    “Hello,” I reply, suddenly feeling very awkward. “I’m so sorry to disturb you.”
    “Nonsense! It’s not a disturbance at all. Come in!”
    I find a smile and step farther inside. “Is Caitlin around?”
    “She’s at the library, trying to track down an old manuscript for me,” he replies. “Friedrich Schiller’s Vom Erhabenen . Are you familiar with it?”
    “Uh, I don’t think so, no.” I glance back at the door, wishing I could will my way back out of it.
    Dr. Mann motions for me to sit, then turns back to the long string of variables, symbols, and numbers on the board, tapping his nose thoughtfully as he examines his handiwork.
    “What is it?” I ask.
    “I’ve been calling it the destiny force,” he says.
    I wait for him to elaborate, but he doesn’t. “The destiny force,” I repeat.
    Dr. Mann nods. “I am attempting to calculate the force—the pull, if you will—of a person’s predestined future.”
    “So you believe in fate,” I say.
    Dr. Mann pauses thoughtfully before answering. “I believe each of us was uniquely created for a specific purpose designed by the Creator, and that, because of that, there are certain things in our lives that we are destined by Him to do. The rest, I think, is soft clay: left entirely to the defining influences of choice, chance, and circumstance. And luck! Don’t forget luck.” He touches the capital L in his equation with his fingertip, leaving an imprint in its base. “The trick,” he says then, “is how to determine which is which.” He smiles. “But I’m afraid there’s no equation for that.”
    Staring at the blackboard, I let my gaze blur. Every life, an equation. Who’s writing mine?
    I look at Dr. Mann. “Chance and luck and all that aside . . .” The old man’s eyebrows shoot up at my wholesale