David Brin's Out of Time

Teens from across time unite to prevent interstellar war in the twenty-fourth century, in this science fiction adventure. Earth is a utopia in the year 2347. Crime, disease, and war are no more. Humanity can travel far and wide through space. But when crisis strikes, the adults are powerless to help. Twenty-fourth-century teenagers are smart and willing, but they'll need help from Operation Hourglass. With time-yank portals, humanity can search through the past to find teens with the necessary qualities to handle whatever trouble comes their way . . . In 1999, Adam O'Connor keeps ending up in trouble. After his latest dumb stunt, he's facing suspension-only to get yanked into the future to face something much worse-a diplomatic meeting between humans and the warlike K'Lugu and Devlins. With the help of a twenty-fourth-century girl, a boy from 1938 Germany, and an enslaved child from 1883 Brazil, Adam must find a way to maintain peace, or there's sure to be interstellar war. Maybe that school suspension looks pretty nice right about now . . . Winner of the Hal Clement Award for Best Young Adult Science Fiction Novel

In this action-packed science fiction adventure, teens from across time must save a scientific base from a destructive-yet adorable-threat. Twenty-fourth-century Earth is a utopia, but when crisis arises aboard a space station on the edge of the solar system, the adults are powerless to help. The teens of this era are amazingly intelligent but they lack the necessary grit for the challenge. Their only option is to turn to Operation Hourglass . . . For five years, Operation Hourglass has yanked resilient teenage heroes from the past and sent them on an array of dangerous missions. This time? A spirited girl and brainy boy from 1999 and a cabin boy from Sir Francis Drake's ship in 1579 join forces with a twenty-fourth-century girl and an unreliable robot to save a scientific base that's being threatened by dangerous, hive-mind creatures. The trouble is the little guys are just so cute and fuzzy . . . Winner of the San Diego Book Award for Youth Fiction

Teens from across time are pulled into the twenty-fourth century for an interstellar rescue mission in this action-packed science fiction series debut. Life is easier in the year 2345, since humanity has created a utopia with no more war, disease, or crime. Only now, Earth is in a dire situation, one which the adults are powerless to help. A group of teenagers step up to the challenge, but they'll need help. . . . Enter Operation Hourglass . . . A team of heroes-champions of their times, spanning history-is assembled, each of them known to have the skills, grit, and instincts to handle crisis. From the twentieth and twenty-first-centuries: a high-school basketball star and a smalltown brainiac. Joining them: a tenth-century Viking and a young thief from nineteenth-century London. Together they must rescue a human star settlement from mysterious, threatening, three-eyed aliens. But even if they survive and successfully complete their mission, there's still the matter of returning everyone back to their pasts . . .

In this thrilling time-travel adventure, a teen survives a modern-day disaster only to be chosen to lead a space mission hundreds of years in the future. There's no disease, crime, or war on twenty-fourth-century Earth, and new technology allows humanity to travel across the universe. But the adults can't go everywhere. Only the teenagers can teleport across space and time, which becomes a problem when disaster strikes, and those kids need help. Fortunately, Operation Hourglass comes to the rescue. Back in 2021, Olivia Becker has lost everything to a raging wildfire that claimed her home and possessions. Even worse, Olivia's dad has taken her to live with his fiancée and her kids. Olivia would rather be anywhere else, and thanks to Operation Hourglass, now's her chance. She is chosen to lead a team of other time-yanked teens from across history on an interstellar rescue mission. There is Najwa, a nineteenth-century Javanese girl; Leonidas, an athlete from ancient Greece; and Everet, a twenty-fourth-century pilot. Together with the floating AI named Giotto, they jump to the beautiful planet Noros, where furious storms threaten three hundred stranded teens before time runs out . . .

Teens from across time band together In the twenty-fourth century to stop a destructive AI threat in this action-packed science fiction adventure. Technology has taken humanity far by the twenty-fourth century. Earth is free of war, disease, and crime. But when crises strikes far from home, the adults are powerless and the teens of the era need help. Luckily, there's Operation Hourglass! The alien species Tarn have come to Earth's solar system to make a trade with humanity: they get Jupiter's moon Europa, and humanity gets a planet of their choosing. To negotiate the treaty, Operation Hourglass assembles a team. From the year 2022 there's Bronx high schooler Meagan Cohen; Kim Dae-Jung from 1930s Korea; Parrette, a fifteenth-century companion to Joan of Arc; and Karter, a cybernetically-enhanced boy from the Troubled Times, decades in Meagan's future. Before they can get down to business, disaster strikes. Sabotage unleashes the advanced artificial intelligence Archimedes, a rogue AI bent on killing anything that tries to stop its bid for freedom and dominance! Now the team must race across the solar system before Archimedes destroys time itself . . .