Abaddon’s Gate : Book 3 of the Expanse (now a Prime Original series)

The third book in the New York Times bestselling Expanse series. NOW A MAJOR TV SERIES FROM NETFLIX For generations, the solar system – Mars, the Moon, the Asteroid Belt – was humanity’s great frontier. Until now.
The alien artefact working through its program under the clouds of Venus has emerged to build a massive structure outside the orbit of Uranus: a gate that leads into a starless dark. Jim Holden and the crew of the Rocinante are part of a vast flotilla of scientific and military ships going out to examine the artefact. But behind the scenes, a complex plot is unfolding, with the destruction of Holden at its core.
As the emissaries of the human race try to find whether the gate is an opportunity or a threat, the greatest danger is the one they brought with them.