Code of Conduct by Kristine C. Smith 1999
Captain Jani Killian had been Evan Van Reuter's lover eighteen years ago, when a Commonwealth diplomatic corps, sent to establish peaceful relations with the alien idomeni, took sides in a civil war.
Jani was presumed killed in the ensuing bloodbath, and Evan went on to become the Commonwealth's Interior Minister. But Jani survived as well more or less. Doctors gave her a new face and patched her broken body together with illegally obtained idomeni genetic materials.
They healed her of everything but her memory of the desperate actions she had taken -- sure to result in summary execution should Commonwealth authorities discover her existence. Which makes it unwise to refuse Evan's request for help in solving the mystery of his wife's death.
There is no shortage of suspects, and the trail draws Jani back into the trauma of Rauta Shiraa and secrets long buried there, secrets someone has killed to protect. If she isn't careful, she'll wind up the next victim -- assuming her own body doesn't kill her first. For after eighteen years, her rebuilt body is failing. Jani is dying. Or is she being reborn?