I've been pondering the tie-in between the Dead series and the Evolution River series. Last night about 2 am I think I have it, and characters will change. Still working out the details, but the frame is there. It will leave the door open for more adventures of Nick and Kiki. The tie-in happens in the transition in time between the end of Sea Species and the beginning of The Envoy.
Meanwhile, I resubmitted the epub file of Penelope because Kobo claimed the fonts weren't embedded properly.