Part 1 (1/2)

A Pair of Docks.

Jennifer Ellis.

The Derivatives of Displacement.

* Position is the 0th derivative of displacement.

Displacement indicates the change in position of a point, particle, or object. *

Chapter 1.

Coventry Hill.

Abbey added the last valence sh.e.l.l to her ionic bonding diagram of sodium chloride and paused to listen. Instead of the usual clack, clack, clack of Simon's computer keyboard, the clatter of containers of metallic objects being overturned and drawers being opened and closed echoed down the hallway.

Abbey moved on to covalent bonds.

Simon sauntered past her and down to the crypt-their joking name for the dark and uninviting bas.e.m.e.nt of the split-level rancher they shared with their parents and Abbey's twin, Caleb. The sound of storage bins being dragged across the floor drifted up the stairs. Simon returned to the kitchen and went to the fridge where he filled two water bottles and made four salami-and-lettuce sandwiches, wrapping each methodically in wax paper.

”What are you doing?” Abbey asked.

”Running away,” Simon said.

”No, seriously.”

”None of your business.” His eyes, so blue they bordered on purple, met hers unflinchingly. Her heart skittered a little. He pulled his black toque over his head.

”I'm going out,” he said. ”To a friend's. Tell Mom I'll be home by eight.”

”But...” Abbey started, the words you don't have any friends dying on her lips.

Simon lifted his chin slightly as if to challenge her, and then took his sandwiches and water bottles and descended the stairs. The bas.e.m.e.nt door slammed.

Abbey drew five valence electrons for nitrogen before placing her pencil against the top of her notebook. Simon never went out after school. She rose and went to the picture window in the living room. The speckled gray of the empty road curved away from their drive and descended into town. She crossed the living room to the window that looked out onto the base of Coventry Hill, the small wooded mountain area that ab.u.t.ted their home on the edge of the town, and saw Simon's black toque disappearing up the path into the afghan of green.

Abbey grabbed her new pink and orange American Eagle cardigan and slipped on her sneakers. She eyeballed Farley, their Chesapeake Bay Retriever, curled in a circle on his bed in the living room. Farley would probably eat Mrs. Forrester's fish fertilizer again. Best to leave him behind. Abbey paused on the doorstep. How long would this take, really? Not long, she hoped. But who knew when her parents would be home? She thrust her key into the lock, turned it, and headed across the street.

The back of Caleb's gray t-s.h.i.+rt, Levis, and blue and tan Adidas sneakers stuck out from underneath Mrs. Forrester's camellia bush. Mrs. Forrester's autistic adult son, Mark, waved wildly at Abbey from inside the house. Mark's stares gave her a riff of unease deep in her gut. She waved back and checked her watch. Four o'clock. Still time. She had to finish her Chem 12 lab before dinner.

”Cale?” she said.

Her twin's brilliant red head popped out from under the glossy green leaves. ”Yes?”

”Simon packed a bunch of stuff, including food, and said he was going to a friend's. Then he took off up Coventry Hill.”

”Our Simon? Simon Sinclair, who never leaves his computer lair, has gone hiking?”

”We'd better go after him.”

”What? We're going to stalk our older brother? What if he's on a date?”

”There's something wrong, Cale. He packed too much stuff and I saw Russell Andrews pus.h.i.+ng him around again today. He looked even worse than usual. I'm worried.”

Caleb c.o.c.ked his head to the side and shrugged, his quintessential gesture. He shrugged at everything, whereas Abbey stomped. She wondered if it was some weird yin and yang of body parts that developed in utero. For every action, there is an equal and opposite reaction. The girls at school thought Caleb was a laid-back surfer kind of dude, which apparently they found wildly attractive, and Caleb played up the persona. They probably thought he was dumb, but Abbey knew his shrugs meant he was thinking. He always liked to consider the situation, and looking like a silent jock bought him time. ”I'm going after him,” Abbey continued, ”and I need you to come with me.”

Caleb lowered his shoulders and nodded, placing his clippers next to the bin of garden waste. ”Don't you think we should text Mom instead? I'm on the clock.”

”Mom's way too busy. The election is in two weeks. Besides, what are we going to say? Simon went out for a hike? She would think that was lovely or some stupid thing.”

Abbey turned and marched to the edge of the cul-de-sac that led to the hill. Mark banged the window with his fist as they left, yelling something at them. This was not an infrequent occurrence. Mark yelled a lot. It was frightening to see a large man with dark stubble and hunched shoulders throw his body around like that. There was a lot of ma.s.s there. Momentum equals ma.s.s times velocity, Abbey whispered in her mind-her stupid brainiac mind-feed, as her brothers called it-always running. She tried not to imagine Mark hurtling through the window. Acceleration due to gravity equals nine point eight meters per second squared. Abbey s.h.i.+vered slightly in the fall air.

”What's up with Mark today?” she asked, thumbing her hand at the window. ”He's even more agitated than usual.”

Caleb just shrugged.

Abbey started up the path, her legs already feeling fatigued. Perhaps she ought to stop skipping P.E. to go to the chemistry lab. Caleb fell into an easy step beside her. She peered through the dense foliage. The intertwining greens of tree and bush made her eyes cross.

”I heard Russell telling Simon outside homeroom this morning that he better not let him down. Russell looked really mad. Something's up.”

Caleb's fingers closed around Abbey's arm while she spoke, and he pulled her into the bushes, the freckled finger of his other hand extended.

A few hundred meters away, Simon was crawling around on the forest floor in front of a rosebush dotted with pink flowers, groping at something on the ground like a blind person. And as if this weren't enough, there was a frantic urgency to his movements that alarmed Abbey.

”What is he doing? Is he hurt? We should go help him,” Abbey hissed.

Caleb didn't move, and maintained his grip on her arm.

Abbey turned and glared at him, trying to wrench away. What if Simon had taken drugs or something and was sick? She couldn't imagine him doing that, but she knew other kids at school did. What if Simon had finally capitulated? She tried to push Caleb's hand away, but he outweighed her by about forty pounds. Unlike Simon, who remained reed-thin, Caleb had already started working out at the gym. She swatted at him. Then he went strangely bug-eyed, let go of her arm, and lurched to his feet.

Abbey spun around.

Simon was gone.

Caleb launched up the hill. Abbey chased after her twin, searching the trees for her older brother.

”Where did he go?” Abbey asked, her voice tight and wan with the exertion.

”He just vanished.”

”That's impossible. He must have wandered off somewhere.” She faced into the trees and called out a defiant, ”Simon! Si! It's us. It's Abbey and Caleb.” Her words came out as a tinny wail.

Caleb tugged at her arm again, his normally dancing green eyes deadly earnest. ”Ab, I'm not kidding you. He was there one second, and then he was gone.”

Bile rose into her throat. People did not just disappear. It was theoretically impossible.