When you step into a time machine, fax yourself through a "quantum foam wormhole" and step out in feudal France circa 1357, be very, very afraid. If you aren't strapped back in precisely 37 hours after your visit begins, you'll miss the quantum bus back to 1999 and be stranded in a civil war, caught between crafty abbots, mad lords and peasant bandits all eager to cut your throat. You'll also have to dodge catapults that hurl sizzling pitch over castle battlements. On the social front, you should avoid provoking "the butcher of Crecy" or Sir Oliver may lop your head off with a swoosh of his broadsword or cage and immerse you in "Milady's Bath", a brackish dungeon pit into which live rats are tossed now and then for prisoners to eat.

This is the plight of the heroes of Timeline, Michael Crichton's thriller. They're historians in 1999 employed by a tech billionaire-genius with more than a few of Bill Gates' most unlovable quirks. Like the entrepreneur in Crichton's Jurassic Park, Doniger plans a theme park featuring artefacts from a lost world revived via cutting-edge science. When the project's chief historian sends a distress call to 1999 from 1357, the boss man doesn't tell the younger historians the risks they'll face trying to save him. At first, the interplay between eras is clever but Timeline swiftly becomes a swashbuckling old-fashioned adventure, with just a dash of science and time paradox in the mix. Most of the cool facts are about the Middle Ages and Crichton marvellously brings the past to life without ever letting the pulse-pounding action slow down. At one point, a time-tripper tries to enter the Chapel of Green Death. Unfortunately, its custodian, a crazed giant with terrible teeth and a bad case of lice, soon has her head on a block. "She saw a shadow move across the grass as he raised his ax into the air." Try not to turn the page!

Through the narrative can be glimpsed the glowing bones of the movie that may be made from Timeline and the high tech computer game that should hit the market in 2000. Expect many clashing swords and chase scenes through secret castle passages. But the book stands alone, tall and scary as a knight in armour shining with blood. —Tim Appelo

In his sensational international bestseller, the preeminent scientist and outspoken atheist Richard Dawkins delivers a hard-hitting, impassioned, but humorous rebuttal of religious belief. With rigor and wit, Dawkins eviscerates the arguments for religion and demonstrates the supreme improbability of the existence of a supreme being. He makes a compelling case that faith is not just irrational, but potentially deadly. In a preface written for the paperback edition, Dawkins responds to some of the controversies the book has incited. This brilliantly argued, provocative book challenges all of us to test our beliefs, no matter what beliefs we hold.

Mind- and reality-bending drugs feature again and again in Philip K. Dick's hugely influential SF stories. A Scanner Darkly is the novel that cuts closest to the bone, drawing on Dick's own experience with illicit chemicals and on his many friends who died through drug misuse. Nevertheless it's blackly farcical, full of comic- surreal conversations between people whose synapses are partly fried, sudden flights of paranoid logic, and bad trips like the one whose victim spends a subjective eternity having all his sins read to him, in shifts, by compound-eyed aliens. (It takes 11,000 years of this to reach the time when as a boy he discovered masturbation.) The antihero Bob Arctor is forced by his double life into warring double personalities: as futuristic narcotics agent "Fred", face blurred by a high-tech scrambler, he must spy on and entrap suspected drug dealer Bob Arctor. His disintegration under the influence of the insidious Substance D is genuine tragicomedy. For Arctor there's no way off the addict's downward escalator, but what awaits at the bottom is a kind of redemption—there are more wheels within wheels than we suspected, and his life is not entirely wasted. In a just world this harrowing novel, the 20th selection in the Millennium SF Masterworks, would have matched the sales of Trainspotting. —David Langford

"The Sign of the Four" is Sir Arthur Conan Doyle's follow-up to his immensely successful "A Study in Scarlet", where we first meet one of the most famous literary detectives of all time, Sherlock Holmes. "The Sign of the Four" is the mystery surrounding the disappearance Miss Mary Morstan's father. Every year on the anniversary of Miss Morstan's father's disappearance, Mary receives an anonymous gift of a priceless pearl. Miss Morstan solicits the help of Sherlock Holmes and Doctor Watson to unravel the identity and motive of her anonymous benefactor.

"A Study in Scarlet" is the first published story of one of the most famous literary detectives of all time, Sherlock Holmes. Here Dr. Watson, who has just returned from a war in Afghanistan, meets Sherlock Holmes for the first time when they become flat-mates at the famous 221 B Baker Street. In "A Study in Scarlet" Sherlock Holmes investigates a murder at Lauriston Gardens as Dr. Watson tags along with Holmes while narratively detailing his amazing deductive abilities.

He's rude, arrogant, cold, unfriendly, and easily bored. But nobody minds, because Sherlock Holmes is a genius at solving mysteries. This collection of some of Holmes's most intriguing cases includes unabridged tales of blackmail, lost fortunes, and, of course, murder.

Adobe Photoshop 5.0 for Photographers bridges the differences and illustrates the connections between traditional, hands-on, chemically intensive photographic processing and manipulation and its computer-based alternative. With its graphically rich examples and detailed diagrams of Photoshop 5.0's user interface, this book will easily transition users with an eye for images into the digital methodology.

Adobe Photoshop 5.0 for Photographers makes no assumptions about the reader's level of proficiency with the popular software. Instead, it begins with an examination of the many means of acquiring images (the fuel for Photoshop) through digital cameras, scanners, and from CD-ROM collections for your PC. Once you've set up the necessary hardware, the book walks you through Photoshop's tools in thematically arranged sections like "montage" and "image repair and retouching." Traditional photographic savvy is well-placed throughout the book, particularly during the discussion of color-toning images (like those in sepia-toned photos) in which this book contrasts the chemical bleaching and dying method of old with Photoshop's Duotone tool.

The accompanying CD-ROM includes tutorial movies related to the examples used in the book. Any "through the lens" photographer considering abandoning the darkroom for a graphics workstation will find Adobe Photoshop 5.0 for Photographers to be required reading. —Ryan Kuykendall