Bliss is first introduced in Foundation's Edge to escort two Foundation men, Golan Trevize and Janov Pelorat, to their reception on planet Gaia. Bliss, like all Gaians, has an enormous affinity for life and can't bear to see life destroyed. She is long distrusted by Trevize while his partner, Pelorat, is quickly fascinated and they become lovers.
Particularly in Foundation and Earth, Bliss serves partly as a way of exploring the narrative, as she and Trevize engage in frequent debates. Bliss acts as an advocate for Gaia/Galaxia while Trevize, still somewhat uncomfortable with the decision he makes in Foundations' Edge, argues for individuality. As both an individual and an extension of the Gaia group-mind, Bliss is extremely intelligent and easily able to debate with Trevize, despite his skills as a politician.
In Foundation and Earth, Bliss leaves Gaia with the two men, helping them in their search for Earth. Because Bliss is a Gaian, she possesses considerable mentallic powers, which are often used as a plot device in Foundation and Earth to help her companions escape from dangers that they encounter during their quest. She commonly uses her empathic and telepathic powers to help deal with dangerous people and creatures. In addition, she also exhibits psychokinetic abilities as well as the power to help purge others of disease-causing organisms. At the climax of Foundation and Earth she, as an avatar of Gaia, bears witness to Trevize's explanation of why he decided in favor of Galaxia as humanity's best option for future survival.