From High Fjord, Eden, Phoenix, and Tennan travel to the frozen surface of new greenland, landing in Sarqaq, which is mostly a set of surface landing strips and related facilities set into fixed permanent ice near the northern polar region. There they took a ride down through the miles-thick ice to a submerged submarine port, where they took a really-really fast sub voyage to Upermavik, which is an "anchored city" attached near the sea floor deep under the ocean. There they spent time with Suraad, who showed them around for a few days.
During one of their sightseeing trips, they visited a large park-like area housed in a torus-shaped area of the city, with a central water-column and lots and lots of glass, and watched sea life, especially huge squid-like creatures, feeding. While there, they were detained, for lack of a better word, by some unidentified security agency, who's operatives are huge 8-foot-tall humans. After some rash decisions on the tram back to the detention / interview center, they had a relatively cordial discussion with their captors, and were released. They were warned maybe they should avoid the local LG representative, named Sev Derstine, who seems to have something against Sara Riven.
They were also told that there is a local organization known as Human Potential, that may seem the team as some sort of threat (because HP doesn't like unmodified humans), and the security folks want to use the team as bait to lure HP into disgracing itself. The team has basically agreed to this, but it hasn't gone forward yet.
Meanwhile, Cal met with Aramis and Nostral on a station in the Ruin system that had been . . . forcibly cleaned of its previous inhabitants. Nostral asked some questions, particularly about his experiences at IBI, and offered some enhancement technology similar to that received by Two, which Cal accepted. Cal then departed via fast courier back to Mwenye and then on to New Greenland, where he meets up with the rest of the team.
The team has a couple of discussions among themselves and with Tennan; Tennan describes herself as a "Radical" and seems to see politics on Roanoke as a struggle between Radicals and Conservatives. She describes some of the long-distant history of the cluster, a time 6,000+ years ago when the people of Roanoke used some technology to move entire planets through the slipstreams and into the Roanoke system, where they were broken down for raw materials for the ring. She indicates this is the reason for the resource-poverty of Mwenye, Tesla, Ruin, and Reich V. She also indicates that the recent (as-in 300 years ago) destruction-by-asteroid-impact of the Mwenye homeworld was caused by this action 6,000 years ago.
The team goes out to dinner, and on the way back to their hotel they are stalked by 6 or 8 people who are using human enhancement devices to communicate. The team calls the authorities, who (it seems) send a drone to investigate, but the drone is knocked out as it exits the area.