More like a 4.5! Morgan returns to sci-fi after his diversion into high fantasy (which I found as much a slog to read as he did apparently, to write). A return to his Thirteen/Black Man setting, extrapolated into the 'wild frontier' phase of colonisation. Mars as a dreary frontier town with all the usual corruption and dirt you would expect from such a setting. This had Morgan's trademark noir trappings, hard boiled and two fisted etc. The technological extrapolations he comes up with are always well bedded into the story and make a lot of sense. I enjoyed this a lot even if the protagonist was straight from 'Richard Morgan Central Casting'. Highly recommended.