Treason by Peter David

The latest in the New Frontier series brings the Excaliber back to New Thallon when the newly widowed requests that Doctor Selar attends the birth of her son. When the Excaliber leaves, Makenzie Calhoun contacts his son, Xyon, to ask him to check in on Robin's mentally fragile sister in law Kalinda- and he narrowly save Robin , Kalinda and the newborn. Meanwhile, Doctor Selar tries to unravel the mystery of a mysterious Hermat picked up from a derelict- and what s/he might mean to the lifespan of her son. A story of betrayal and redemption ensues, with more of the loss that seems to permeate recent Star Trek books. I especially enjoyed reading descriptions of Robin nursing little Cwansi.