Vox Sola

Hoshi thinks she is to blame for a series of misunderstandings that sent a group of visiting aliens off the Enterprise in a huff. As the Kreetassans depart, a strange, symbiotic alien creature boards Enterprise capturing a few crew members, including Archer and Trip. This unidentifiable parasite cocoons them in its web, feeding off their bodies to survive.

Synopsis adapted from TVmaze (CC BY-SA 4.0)