The team plans to renew contact with Dominé, but in the end he renews it willingly and eagerly with Phoenix.  There's some back-and-forth, but not much new is learned, and eventually he invites her on a five-day trip to "Reef City", an underwater city near a large volcanic / thermal vent formation where tourism, research, and energy generation share the location.  Cal and Eden head to Reef City the day before Phoenix is scheduled to leave, in order to be there for support.  Cal has Tennan fabricate an audio bug that lives under the skin on Phoenix's left bicep and masquerades as implantable birth control.  It uses her handcomp for communication and transmits in bursts.