When the Starbug crew were flying through a Psiren-infested asteroid belt, they received a transmission from one of the other ships in the same situation. The distress call came from a woman who identified herself as Captain Tau of the SCS Pioneer. She was shown battling the Psirens over the video screen, but was shot dead only for her weapon to be picked up by Kristine Kochanski. Both were revealed to be illusions created by the Psirens.
- Captain Tau is named after Red Dwarf's captain in the American pilot episode of Red Dwarf (1992). Both characters died after speaking only a few lines.
- Although Kochanski was obviously an illusion, it is possible that Tau may have been a real person and an earlier victim of the Psirens.
- During commentary for this episode, the cast bemoaned that Anita Dobson's character was given a much cooler weapon than they ever got.
- When the producers approached Brian May about doubling for Lister's guitar work in "Psirens", they decided to also ask May's partner Anita Dobson if she would consider a small role. Unfortunately, May was committed workwise at the time but Dobson was available, and agreed to take part. The producers regretted that they did not have a more substantial part for her.