Murtry does not show up again in the books.
Many people thought Cibola Burn, the book season 4 is based upon, to be the slowest paced. I liked the book, and though they did a nice job weaving the plots together. I lament some of the things they cut, however, including most of the things that happened in orbit.
Actually, only the the events on Ilus/New Terra were from that book. The other events were pulled forward from book 5 (Nemesis Games) and the novella Gods of Risk . Season 5 will cover the rest of Nemesis Games and (hopefully) the novella The Churn.
If you are up for a good ride, the audio book versions of The Expanse, narrated by Jefferson Mays, are astounding.
LEAF '13 SL+Prem (mfg 12/13, leased 4/14, bought 5/17, sold 11/18, 34K mi, AHr 58, SOH 87%)
Tesla S 75D (3/17, 45K mi)
Tesla X 100D (12/18, 23K mi)
ICE free since '18
100K+ 100% BEV miles since '14