The Shadow Within — Jeanne Cavelos

THE DARKENING LIGHT
Anna Sheridan has two passions--her husband, John, and the mystery surrounding some intriguing artifacts found during a mission on a distant planet called Z'Ha'dum. Now she gets orders to become the science officer on the follow-up mission scheduled for the spaceship Icarus. Happy, young, beloved, and brilliant, never, has a woman had so much to live for. Or so much to lose.

THE SHADOW WITHIN
While John, recently promoted to the rank of captain, struggles with his new command on the Agamemnon, Anna begins to assemble her science crew...and makes her first mistake. She signs on Dr. Morden, a highly credentialed translator whose heart hides a weakness that can cost Anna her life...or her soul. Her second mistake is to underestimate the danger on Z'Ha'dum. What is awaiting the Icarus near the rim of known space is an unimaginable horror. What is awaiting Anna Sheridan is an explosive destiny...and a dark future that can crush her husband's dreams and a terror that can come back to haunt us all.