The alien artifact that once haunted humanity has finished its work. Beyond the orbit of Uranus, it has raised an enormous Ring — a gate opening onto a vast, silent space that should not exist, and onto questions no one in the solar system can answer.
Earth, Mars, and the Belt each send ships to study it, and Jim Holden and the crew of the Rocinante are pulled along with the flotilla, unwilling celebrities at the frontier of a new age. But not everyone aboard is there for science. Among the fleet travels a young woman under an assumed name, nursing a private vendetta that could destroy Holden — and a Methodist pastor who signed on as a witness to history, hoping to hold a fracturing expedition together.
When humanity crosses the threshold of the Ring, old rivalries, raw fear, and blind ambition follow it through. In the strange country on the far side, the choices of a handful of people may decide whether the human race steps forward into the stars or brings ruin down on itself.
The third novel of The Expanse turns the series outward, trading the politics of a single solar system for the awe and terror of a doorway to everywhere.