In 1758, Yeh was accidentally left in Alaska by a member of the Great Houses. Soon after this Yeh met Compassion, who was also left in Alaska after her companion from the Homeworld had left her. Compassion offered to "give [Yeh] a lift" while Compassion searched for her previous companion; the two travelled together for three years.
During their time together, Yeh persuaded Compassion to meet with the War King. Yeh gathered plenty of knowledge of the War in Heaven during her travels and wrote that Compassion thought the enemy was just a distraction and the true threat was from "family". Compassion later suggested that the emergence of House Lucia would be the indication of the real threat showing itself.
Yeh and Compassion were present at the assassination of R. B. Nevitz.
One of their most notable misadventures took place on the frontier in time. There, Compassion became greatly distressed upon finding the remains of the 103-form timeship "Percival"; she then confronted the War King in the middle of a state dinner. Compassion created a second pact with the War King and the head of House Mirraflex shortly before she stopped travelling with Yeh.
After leaving Compassion and settling down, Yeh wrote her (allegedly fictitious) memoir Fantastical Travels in an Infinite Universe, where she called herself "Yvette Carlton" and Compassion "Laura". (PROSE: The Book of the War)
Behind the scenes
- Before her first official appearance in The Book of the War, Carmen appeared as a companion of the Eighth Doctor in Ian McIntire's unlicensed short story Schrodinger's Botanist from the 1998 charity anthology Perfect Timing. In that story, she was captain of an ElleryCorp shipping vessel whose only other passenger was an artificial intelligence named LEO. When the Eighth Doctor arrived on their ship, he discovered that ElleryCorp was using Carmen as an experiment on human sanity in isolation. LEO tried to kill them both, but the Doctor stopped it and left with Carmen.
- "Carmen Yeh" is an anagram of "Archenemy".