The view is fine up here. I can look out across the world and see everything. For instance, I can see a fifteen-year-old boy and his brother.

1

David Case's baby brother had recently learned to walk but he wasn't what you'd call an expert. He toddled past his brother to the large open window of the older boy's room. There, with a great deal of effort, he pulled himself onto the windowsill, scrunched up like a caterpillar, pushed into a crouch, and stood, teetering precariously, his gaze fixed solemnly on the church tower a quarter mile away.

He tipped forward slightly towards the void just as a large black bird swooped past. It paused and turned an intelligent red eye to meet the child's.

"Why not fly?" suggested the bird, and the boy's eyes widened in delight.

Below them on the street, a greyhound stood motionless, his elegant pale head turned in the direction of the incipient catastrophe. Calmly the dog shifted the angle of his muzzle, creating an invisible guyline that eased the child back an inch or two towards equilibrium. Safer now, but seduced by the fact that a bird had spoken to him, the boy threw out his arms and thought, Yes! Fly!

David did not hear his brother think "fly."

Something else made him look up. A voice. A finger on his shoulder. The brush of lips against his ear.

So that's where we start: One boy on the verge of death. Another on the verge of something rather more complicated.

In the instant of looking up, David took the measure of the situation, shouted "Charlie!" and lunged across the room. He grabbed the child by the cape of his Batman pajamas, wrapped his arms around him with enough force to flatten his ribs, and sank to the floor, squashing the boy's face into the safe hollow beneath his chin.

Charlie squeaked with outrage but David barely heard. Panting, he unpinned him, gripping the child at arm's length.

"What were you doing?" He was shouting. "What on earth did you think you were doing?"

Well, said Charlie, I was bored just playing with my toys and you weren't paying attention to me so I thought I would get a better look at the world. I climbed up on the window which wasn't easy and once I managed to do that I felt strange and happy with nothing but sky all around me and all of a sudden a bird flew past and looked at me and said I could fly and a bird hasn't ever talked to me before and I figured a bird would know what he was talking about when it came to flying so I thought he must be right. Oh and there was also a pretty gray dog on the pavement who looked up and pointed at me with his nose so I didn't fall and just when I was about to leap out and soar through the air you grabbed me and hurt me a lot which made me very cross and I didn't get a chance to fly even though I'm sure I could have.

The little boy explained all this slowly and carefully, so as not to be misunderstood.

"Burr-dee fly" were the words that came out of his mouth.

David turned away, heart pounding. It was useless trying to communicate with a one-year-old. Even if his brother had possessed the vocabulary, he couldn't have answered David's question. Charlie did what he did because he was a dumb kid, too dumb to realize that birds don't talk and kids can't fly.

My god, David thought. If I'd been two seconds slower he'd be dead. My brother would be dead but I'd be the one shattered, crushed, destroyed by guilt and blame and everyone everywhere for the rest of my life whispering He's that kid who killed his brother.

Two seconds. Just two seconds were all that stood between normal everyday life and utter, total catastrophe.

David sat down hard, head spinning. Why had this never occurred to him? He could fall down a manhole, collapse of a stroke. A car crash could sever his spinal cord. He could catch bird flu. A tree could fall on him. There were comets. Killer bees. Foreign armies. Floods. Serial killers. There was buried nuclear waste. Ethnic cleansing. Alien invasion.

A plane crash.

Suddenly, everywhere he looked he saw catastrophe, bloodshed, the demise of the planet, the ruin of the human race, not to mention (to pinpoint the exact source of his anxiety) possible pain and suffering to himself.

Who could have thought up a scenario this bleak?

Whoever (whatever) it was, he could feel the dark malevolence of it settling in, making itself at home like some vicious bird of prey, its sharp claws sunk deep into the quivering gray jelly of his terrified brain. He pulled his brother close, tucking him in against his body, pressed his lips to the child's face.

What if . . . ?

He became enmired in what if.

The weight of it wrapped itself around his ankles and dragged him under.

2

A year earlier, David's father had woken him with a shout.

"David, your mother's home! Aren't you interested in seeing the baby?"

Not really, David thought, burying his head in his pillow. I know what a baby looks like.

But then they were in his room, grinning and making inane noises in the direction of a small, serene-looking creature with jet black eyes.

David sat up with a groan and peered at his new brother. OK, seen him, he thought.

"Of course he can't see you yet." His father, superior as ever. "Babies can't focus properly for weeks."

David was about to go back to sleep when he noticed the new baby gazing at him with a peculiar expression of calm authority.

I'm Charlie, said the new baby's eyes, as clearly as if he had spoken the words out loud. Who are you?

David stared.

His brother repeated the question slowly, politely, as if to a person of limited intelligence. Who, exactly, are you?

David frowned.

The baby inclined his head, his face registering something that might have been pity. Such a simple question, he thought.

But if his brother knew the answer, he gave no sign.

This disturbed Charlie. Over the next few months, he tried approaching his parents for answers, but his father was always at work and his mother seemed strangely ill informed on the subject of her older son.

"He's usually on time," she would comment brightly, or "I wish he'd tidy his room more." But nothing about who he was. And when she caught Charlie staring intently at David, she merely thought, How sweet. They're bonding.

But they weren't bonding. Charlie was comparing the David he knew with the Davids he saw displayed around the house in family pictures. The younger Davids looked cheerful and carefree; they held books or bikes or ice creams and gazed at the camera with expressions of trust. The younger Davids kicked balls, swung from trees, blew out the candles on birthday cakes. They had clear edges and cloudless eyes.

But the David that Charlie knew now was wavery and fizzy with nerves. The new David reminded Charlie of a birthday card he'd seen where the picture of a clown shifted gradually into the picture of a tightrope walker, depending on how you tilted it. Exactly when this transformation had begun, the child couldn't say. According to the photos, his brother's outline had begun to blur sometime between playing football at thirteen and losing his status as only child the following year.

Charlie had spent a good deal of his short life worrying about his older brother. Now he paused in the middle of playing Monkey Rides in a Car with Donkey to gather his thoughts. He saw that his recent attempt to fly had been a mistake. It seemed to have nudged his brother past some invisible tipping point and this filled him with remorse. Charlie wanted to make amends, to offer advice on how David could regain his footing. But he couldn't get his brother to listen.

Or perhaps he was listening, but somehow lacked the capacity to understand. This worried Charlie most of all.

Excerpted from JUST IN CASE © Copyright 2011 by Meg Rosoff. Reprinted with permission by Wendy Lamb Books, a division of Random House, Inc. All rights reserved.