"Medusa" was allotted a "huge budget", due mostly to the fact that a replica of the Boston subway had to be recreated. Robert Patrick later called the eventual set "the biggest damned thing I'd seen in my life." Cheri Montesanto-Medcalf and Matthew Mungle, the show's make-up effect producers, used several unorthodox ingredients to create the effect of melted flesh; in addition to the use of normal prosthetic make-up, the two also used a combination of figs and Fruit Roll-Ups.
"Medusa" was written by executive producer Frank Spotnitz and directed by Richard Compton. Reportedly, because of the scope of the episode, a "huge budget" was allotted for the entry. The subway set created for this episode was designed to mirror the actual Boston subway. According to co-star Robert Patrick, "They got us in there, and we did it, and they built a huge subway tunnel set on a soundstage." Patrick later described the set as "the biggest damned thing I'd ever seen in my life." In real life, the Boston subway system is "fondly" called the T, short for the Massachusetts Bay Transportation Authority. In "Medusa", the "T", was changed to an "M" "for fictional purposes".
Paula Vitaris from Cinefantastique gave the episode a slightly negative review and rated it one-and-a-half stars out of four. Despite noting, "after episodes about butt-crawling and vomiting, it's a relief to have one in which people die when their skin and muscles are fried away by microscopic sea creatures called medusas", Vitaris was critical of the plot, likening it to "cliche[d]" 1970's movies that featured the "obstreperous official insisting the plane must fly or the skyscraper is fire-proof, even when the potential for catastrophe is staring him in the face." Spotnitz later admitted during a Reddit IAmA that the episode was his least-favorite that he had written because "the concept just wasn't clear or compelling enough to sustain the hour." 59ce067264