Season 1

Holden, Naomi, Shed, Amos and Alex are crew on the Canterbury. They leave the ship to investigate a distress call. Whilst they're off the ship, it gets blown up by stealth fighters. They broadcast a message to the rest of the solar system claiming Mars did it. They get picked up by a Martian battleship, which also gets blown up. On the way out, Shed is killed, and they take a Martian frigate called the Tachi.

Meanwhile on Ceres, detective Miller is told he's to investigate the disappearance of Julie Mao, heir to the fortune of Mao-Kwikowski Enterprise, who had recently fallen in with a crowd of radical OPA activists. When he gets a few leads, he's immediately fired. He begins investigating on his own.

The people on the Tachi arrive at Tycho Station, run by Fred Johnson, former Earther sergeant who switched sides after a brutal massacre of civilians. Now he works for the OPA, but they don't really trust him that much. He has a second-in-command called Drummer. Fred and Drummer help the crew of the Tachi change the transponder of their ship so they cant be detected by the Martians who think they stole it. Now it's called the Rocinante. They begin investigating who caused the shootdowns of the ships.

Eventually they end up on Eros, following the trail of Julie Mao. They meet Miller, who also was following the trail, and find her dead in a shower cubicle in a hotel, covered in weird blue goop. They get shot at and leave. Bad guys working for an unknown corporation come in and bottle up some goo. Then, all of the alerts in the station go off, and the bad guys start injecting the people with the goop. They get infected and begin to turn into a big biological machine. Before they get infected, everyone manages to escape.

Season 2

They return to Eros not long later to blow it up. They steal a massive generation ship from the Mormons and use it to bash Eros out of the way. But Eros moves and starts trying to crash into Earth. Miller goes inside and talks down Julie Mao's consciousness which is controlling Eros. It ends up crashing into Venus, killing them both. (end of book 1)

On Ganymede, Martian marine Bobbie Draper and her crew are attacked by a mysterious monster. She is the only member of her crew to survive. This fight starts a skirmish in orbit, and ends up destroying some of the orbital mirrors. People are evacuating from Ganymede and the station is about to collapse.

In the chaos, scientist Prax has become separated from his daughter Mei, who was with her doctor at the time of the attack. He is forced to leave the moon and seek refuge elsewhere.

Bobbie Draper is taken to Earth to face a bilateral inquiry into the cause of the events on Ganymede. Sticking to her story about the monster, she is told off by her superiors, and realising they are forcing her to lie because the monster was under their control, and that she was being used as a guinea pig, she switches sides to Earth.

Undersecretary General Chrisjen Avasarala takes Bobbie Draper to the spaceship of Jules-Pierre Mao, Julie Mao's father. When she arrives, she receives a message from another UN elite, explaining that he had betrayed her, and that he and Mao were responsible for the Eros incident as well as selling the protomolecule technology to the Martians.