In Seaglass (Paperback) (ISBN-13: 9798224899548)

Robin is still deep in the Otherworld with ..several versions of the Red Dragon, and two of the mystical items known as the Tarrasque. But her cousin Jay is still missing, probably somewhere in the undersea territories of the Lady Ruin, and she has no idea where Taran, Alan, or Talsin have gotten to. But while she's looking for them, the Red Dragons are looking for a safe place to stop and regroup, and something else is looking for all of them...