Down Trilogy Books in Order

Glenn Cooper’s Down Trilogy imagines what might happen if a piece of cutting-edge physics accidentally punched a hole into a place that looks like hell. It begins in Pinhole, with a massive particle collider buried under London and a small team of people trying to keep it safe.

John Camp, a former soldier now running security for the project, is still wrestling with his wartime past. Emily Loughty, the Scottish physicist in charge, is brilliant, cautious, and one of the few people John lets close. When the collider overshoots its target, Emily disappears and a brutal stranger appears in her place.

The only clue is that the stranger isn’t from our world at all. John volunteers to go wherever Emily has gone and finds himself in Down, a landscape that mirrors Earth but is populated by history’s worst criminals, warlords, and tyrants. Kingdoms rise and fall in endless cycles of violence, and Emily is trapped somewhere inside that nightmare.

In Portal, the once-tiny rift between worlds has widened. Innocent people on the surface are dragged into Down, forcing John and Emily to recruit unlikely allies—a former cop, a television weapons expert, hardened soldiers—for a rescue mission. On our side, MI5 agent Ben Wellington is hunting escapees from Down who are now roaming the English countryside.

By Floodgate, the situation has spiraled. The link between realms is no longer a pinhole or a manageable portal but a gaping floodgate pouring confused, dangerous souls into London. The public finally learns that Down exists, the city slips toward chaos under martial law, and John and Emily must gamble everything on one last journey below to find the only man who might shut the connection for good.

Cooper blends high-octane action with speculative questions about evil, punishment, and second chances. The trilogy moves from claustrophobic tunnels to ruined cities and back to the corridors of power in London, always asking what responsibility the living have toward the damned—and whether anyone deserves to be written off forever.

If you like your thrillers with a strong dose of dark fantasy and big moral questions, the Down books are designed to be read straight through, building tension book by book.