[s15e18] Underworld 2 May 2026

: The story is loosely based on the Greek legend of Jason and the Argonauts , specifically their quest for the Golden Fleece, with "Underworld" serving as a sci-fi retelling of the journey to Colchis. Critical Reception & Production

: You can find this classic episode on streaming platforms like Apple TV or Tubi . [S15E18] Underworld 2

: This serial is notorious for its heavy use of Color Space Overlay (CSO) , a primitive green-screen technique, to create the cave settings. Reviewers from IMDb note that while the lasers and some CSO effects work, others look "simply awful". : The story is loosely based on the

: Critics generally find Part Two to be the weakest segment, describing it as "extremely dull" with roughly 20 minutes of "walking around and gas". Reviewers from IMDb note that while the lasers

In this chapter of the four-part story, the Doctor and his companions explore a slave-labor mining society on a newly formed planet.

: The Doctor discovers troglodytes working in a nebula's core full of caves, overseen by men who use "fumigation" as a means of control.

: The society is controlled by "The Seers," who value radioactive energy over human life.