The universe is a dangerous place for humanity — and it's about to become far more dangerous. Three races that humans have clashed with before have allied to halt our expansion into space. Their linchpin: the turncoat military scientist Charles Boutin, who knows the CDF's biggest military secrets. To prevail, the CDF must find out why Boutin did what he did.

Jared Dirac is the only human who can provide answers — a superhuman hybrid, created from Boutin's DNA, Jared's brain should be able to access Boutin's electronic memories. But when the memory transplant appears to fail, Jared is given to the Ghost Brigades.

At first, Jared is a perfect soldier, but as Boutin's memories slowly surface, Jared begins to intuit the reasons for Boutin's betrayal. As Jared desperately hunts for his "father," he must also come to grips with his own choices. Time is running out: The alliance is preparing its offensive, and some of them plan worse things than humanity's mere military defeat...

“Though a lot of SF writers are more or less efficiently continuing the tradition of Robert A. Heinlein, Scalzi’s astonishingly proficient first novel reads like an original work by the late grand master…The novel’s tone is right on target, too—sentimentality balanced by hardheaded calculation, know-it-all smugness moderated by innocent wonder. This virtuoso debut pays tribute to SF’s past while showing that well-worn tropes still can have real zip when they’re approached with ingenuity.”

--Publishers Weekly (starred review)

“Solid…[Scalzi] sidesteps most of the cliches of military science fiction, delivers fast-paced scenes of combat and pays attention to the science underpinning his premise.”

--San Francisco Chronicle

“Thought-provoking!”

--Entertainment Weekly

“Smartly conceived and thoroughly entertaining, Old Man’s War is a splendid novel.”

--Cleveland Plain Dealer