From School Library Journal
Grade 4-7 - This fast-paced story talks of far-fetched ideas in seemingly ordinary terms, giving somewhat rational explanations for using laptops to travel through time. Dorso, 12, finds himself the brunt of time-travel-related practical jokes - he discovers dead bodies in his school locker, has a strange encounter with Beethoven, and watches as a woolly mammoth appears out of nowhere and throws his pal Frank across the yard. The boys try to figure out what is going on, and soon realize that the incidents are related to Dorso's laptop. When they start unexpectedly jumping back into history, they encounter two time travelers who are playing games with the historical time line through the use of a special chip implanted in their computers. One man tries to change the past, while the other attempts to stop him. The boys theorize that the chip must have also been implanted in Dorso's computer; that's how they get pulled into the game. However, the mystery is not completely solved until they encounter the engineer who designed the chip. The main characters come across as believable individuals - one boy is serious and the other wants to use time travel for "anatomical studies" (viewing naked women). The story should appeal to fans of Paulsen's The Transall Saga (Delacorte, 1998), as well as computer-game fans and reluctant readers. - Diana Pierce, Running Brushy Middle School, Cedar Park, TX Copyright © Reed Business Information, a division of Reed Elsevier Inc. All rights reserved.

From Booklist
Gr. 5-8. Seventh-grader Dorso Clayman has a problem in his futurist world. Every time he opens his locker, he finds something from another time or place. He's determined to find out who is messing with the time continuum before a woolly mammoth tramples him, he's shot with an arrow at Wounded Knee, or, worse, the time fiddlers destroy the world. Luckily, his best friend, Frank (who uses conventional time-travel opportunities to spy out naked women from history), is on his side, and together they can set things right. Paulsen writes with his usual skill, creating believable characters and moving the action along at a fairly fast pace, but the spare story feels as if it should have been expanded into a longer novel, and explanations of the science concepts involved seem complicated for the target audience. Still, this has some fun moments. Try it with rowdy, adventure-loving readers and science-minded kids. It's hard to tell which audience will be the most receptive. Cindy Welch
Copyright © American Library Association. All rights reserved

From the Inside Flap
You ever open your locker and find that some joker has left something really weird inside?

Seventh-grader Dorso Clayman opens his locker door to find a dead body.

Thirty seconds later it disappears.

It’s not the first bizarre thing that has appeared in his locker and then vanished.

Something’s going on.

Somebody has decided to make Dorso and his buddy Frank the target of some strange techno-practical jokes. The ultimate gamesters have hacked into the time line, and things from the past are appearing in the present. Soon, the jokes aren’t funny anymore—they’re dangerous. Dorso and Frank have got to beat the time hackers at their own game by breaking the code, before they get lost in the past themselves.

About the Author
Gary Paulsen is the distinguished author of many critically acclaimed books for young people. He lives in New Mexico and on the Pacific Ocean.

Excerpt. © Reprinted by permission. All rights reserved.
He should have known better and opened his locker more slowly. Some sense should have warned him. There were enough strange things going on; he should be more cautious.

But no. No, he had to come bombing down the hallway and work the last number on the combo on the door and jerk it open without thinking.

There was an adult male hanging inside. Dead. Not only that, but it was a medical cadaver, partially cut open with long pins holding things in. And not only that, but it was an old cadaver.

Runny.

And the stink--Oh, my, he thought, only in different words. Much different words. Oh, my, the stink was positively alive, rolled out in a semigreen cloud, and he could hear flies coming inside from out in the schoolyard, zooming to the odor. Oh, yes, there would be flies. Of course flies. And they would stay around. Last time when he found seven hundred and twenty-one and one-half dead lab rats in his locker, packed in tightly, the flies had stayed for a month even when the rats were gone.

It was a joke. Some joke.

Dorso Clayman held his breath and closed the locker door, looked up and down the hallway to see if anybody was watching. Nobody seemed to be paying special attention but that didn't mean much. Someone might have a small camera on him, getting his reaction on a digit-disk to broadcast later. He decided to play it nonchalant. Cool. As if he always had bodies in his locker.

And it would have worked except that Susan Racher walked down the hall at that moment, right past his locker, and the smell drifting, no, slithering out of the bottom grill on the locker door dropped her cold. Literally. She went down on her knees, grabbing for her inhaler. Susan was one of those who always acted sick but never actually was. But then she keeled over onto her side, one leg jerking feebly. For a second Dorso did nothing. Susan was always faking it.

But this time it seemed real enough--her eyes had rolled back and were showing only white. So he grabbed her by the wrists and dragged her down the hallway past the smell zone. He propped her up against the wall and put her inhaler in her mouth.

"She dead?"

Dorso looked up to see his best friend, Frank Tate, looking down at Susan. "She's going to miss her first class if she's dead," Frank said. "They don't like it if you miss homeroom even if you're dead."

Dorso shook his head. "No. She's just out for a little bit. The smell caught her wrong."

"What smell?" Frank sniffed. "Is there something stinking?"

"You're kidding . . . ," Dorso started, then remembered that Frank had a sinus condition that kept him from smelling things. Frank had once run his bicycle over a dead skunk on the highway without noticing it, even though part of the skunk had stuck to a tire and kept flopping around and around as he rode, the stink blowing up in his face with each rotation. Bulletproof, Dorso thought, a bulletproof nose. "I had a body in my locker."

"Again? Man, don't they ever think of anything else to do to you? Last time they put a dead dog in there, and then there were the lab rats, and of course the time they stuck in the six or seven thousand dead frogs . . ."

"This time it was human. Some medical student's job, it must have been. But old. Really old."

Frank nodded. "Yeah. It would have to be old. That's how it works, isn't it? You can't transport anything current and the system won't go into the future, so it has to come from the past." As he talked he went to Dorso's locker and grabbed the handle. "How did it look?" He jerked the door open.

"Don't--" Dorso started, but then he shrugged. It had been more than thirty seconds, and none of the . . . surprises . . . ever seemed to last longer than half a minute.

"It's gone," Frank said. "Too bad. I might have recognized it from when I did all those medical research scans for my anatomy study."

"You were just looking for naked pictures."

"Still. It's research, isn't it? And at first it wasn't a protected zone. If the government didn't want you to see it they would have put the blocks on the way they did with religion and later with naked pictures."

Dorso left Susan and moved back to his locker. The smell was still almost as strong as it had been when he'd first opened the door, but the body was gone, all traces of it, even the stains. Well, that was good, at least. He held his breath and took out his gym bag. He had gym first period, which was a stupid time to have PE, but he was stuck with it if he wanted to take computer science second period, which he had to do because Karen Bemis took computer science then and he thought if he could be around her enough she might begin to notice him. It hadn't happened in two years but he still had hopes.

His gym bag reeked of the dead body. That meant the smell had gotten into his gym shorts and T-shirt as well.

Great. I'll stink like a cadaver. Just great.

He looked down the hallway where Susan was getting to her feet, her eyes dazed as she leaned against the wall, and for about the ten thousandth time that month he thought maybe it had been a bad idea when the scientists had figured out how to crack time.

FROM THE PUBLISHER

You ever open your locker and find that some joker has left something really weird inside?

Seventh-grader Dorso Clayman opens his locker door to find a dead body.

Thirty seconds later it disappears.

It's not the first bizarre thing that has appeared in his locker and then vanished.

Something's going on.

Somebody has decided to make Dorso and his buddy Frank the target of some strange techno-practical jokes. The ultimate gamesters have hacked into the time line, and things from the past are appearing in the present. Soon, the jokes aren't funny anymore—they're dangerous. Dorso and Frank have got to beat the time hackers at their own game by breaking the code, before they get lost in the past themselves.

FROM THE CRITICS

Publishers Weekly

Paulsen's futuristic novel starts with a bang, as Dorso Clayman discovers a medical cadaver in his school locker ("It was an old cadaver. Runny"). Readers quickly learn that the discovery of a "hologram projector chip" has led to "time projection": anyone with a laptop could now "pull images from the past and project them anywhere." Yet this technology is supposedly governed by the "paradox of time"; individuals can view the past but cannot physically be transported back in time so as to be able to alter history. Dorso is puzzled by a string of computer-generated pranks (in addition to the cadaver, he's been visited by holograms of dead frogs, lab rats and rotting earthworms). But the 12-year-old is mystified when he finds himself face-to-face with Custer, Beethoven and then a woolly mammoth-which was most definitely not a hologram. He and his friend Frank suspect that someone has found a way around the time paradox and that Dorso's laptop is connected to the perpetrator's scheme. As they're transported to various episodes in history (including the Battle of Gettysburg and the Crusades), the duo learns that time hackers are playing a game that might destroy the universe. Readers will be sucked into Paulsen's clever plotting, despite some silly, repetitive bits involving Dorso's younger sister's dress-up games with their cat, and Frank's obsession with conjuring up a naked Helen of Troy. This inventively twisted cyberspace caper may well lure kids more accustomed to surfing the Web than turning pages. Ages 10-up. (Jan.) Copyright 2005 Reed Business Information.

Children's Literature - Della A. Yannuzzi

This short book of fiction by a popular children's writer tells the story of two boys who are the victims of a computer plot to alter time. The story opens with Dorso Clayman finding a medical cadaver in his locker. It is not the first time Dorso has found strange things in his locker. There have been frogs, dead lab rats, and now the cadaver. The strange thing is the offending objects are gone within thirty seconds. Dorso and his friend Frank Tate decide to find out who or what is playing these disgusting tricks. They figure out it has to do with Dorso's laptop. Someone tinkered with it, but who and why? When Dorso and Frank find themselves transported into certain time periods, they know they are on to something, especially when they see someone nearby with a laptop. Then as quickly as they appeared out of time, they are back when that someone touches the laptop. Things get really scary when the objects became real, especially when Frank is roughed up by a woolly mammoth. The boys realize it is not a hologram, but a real mammoth. Dorso is determined to figure out this mystery, but Frank isn't so sure. He wants to go to the authorities, but Dorso says they won't believe their story. Eventually the mystery is solved with an added big reward. Readers will enjoy this lively, fast-moving tale. 2005, Random House Children's Books, Ages 10 up.

Kirkus Reviews