"Thicker Than Water" is the second episode of the second season of Star Trek: The Cantabrian Expeditions and continues the season's first arc aboard Deep Space 4.
The Trill Symbiosis Commission appear aboard Deep Space 4, investigating the joining of Tawana Jonar to the Jonar symbiont, with a special guest in tow: Tawana's father Aumil Killan.
In the meantime, Helena Bourget resurfaces, brokering safe passage for her in exchange for an antidote to bring her mother out of a coma...
- Helena Bourget makes her seasonal debut here.
- Tawana Jonar's father is introduced here, as is support for Tawana's claims in "Catalyst, Part One" and other episodes of unease on Trill.