One Cast Member's Ailment Ended Up Making It Into A M*A*S*H Script

"M*A*S*H" famously pulled from real life across its historic eleven-season run. The team behind the sitcom spoke with actual doctors and nurses who worked during wartime in order to come up with many of the show's most heartbreaking — and hilarious — plotlines. In season 5, though, the show ended up incorporating a real-life event that was a lot closer to home: Father Mulcahy actor William Christopher's battle with hepatitis.

Hepatitis, which in 1977 was still being researched and categorized (the Nobel Prize in Medicine the year before went to a scientist who had discovered the Hep-B virus), was no joke for anyone who contracted it at the time. Unfortunately, Christopher did, and in Suzy Gershman's (née Kalter) 1984 book "The Complete Book of M*A*S*H," he explains that he ended up bedridden for eight weeks. According to one MeTv article (which cites a source who spoke to The National Enquirer, so it may be apocryphal), "He became very sick and many people thought that he wouldn't make it." Luckily, though, thanks to a well-timed shooting schedule and an episode written and directed by star Alan Alda, Christopher was able to remain on the show despite his long absence.

"It was fortunate how it worked out or I might have been taken out of the show," Christopher, who passed away in 2016, shared in Gershman's book. "But it was the year that Fox had a new deal out at the Ranch. The expectation was that we wouldn't have the Ranch, so we had done all the exteriors at one time, early on." The Ranch in question was the outdoor set the cast shot on in Malibu Creek State Park. At one point, the entire area was owned by Fox, and Robert Altman's film version of "M*A*S*H" shot its exteriors in the area before the show took over. In 1976, according to The Los Angeles Times, Malibu Creek State Park opened, and only productions with special permission could continue to film in the region.

This change is likely the one Christopher is referring to, and since the "M*A*S*H" team thought they might not get access to the park, that meant they were able to film more on a soundstage. This was lucky for Christopher. "I was doing exteriors, back at Stage 9, when I got sick," he recalled. "They had to rewrite me, but I was established enough so that I got paid and didn't get written out of the show totally." Luckily, with the amended shooting schedule for the season, Christopher was able to recuperate and return to the show. "I was in bed for eight weeks, and I could have never missed that amount of work if we shot in the normal way, so I guess 'Someone' was watching over me," he shared in Gershman's book.

Not only did the "M*A*S*H" writers rewrite Father Mulcahy to help Christopher get time to heal, but they also incorporated his illness into the show. The much-loved season 5 episode "Hepatitis" — the fourth with Alda's byline on the screenplay — revolves around Hawkeye's attempts to inoculate the rest of the 4077 when Mulcahy comes down with a bout of the disease. "Hepatitis" is mostly remembered for its sweet and silly moments, like when Radar (Gary Burghoff) admits he feels like a late bloomer, and when Hawkeye topples onto a hungover B.J. (Mike Farrell) after doing a handstand. But there's also a scene that's extra resonant in context, in which Hawkeye has to convince Mulcahy to stay in bed. "People are depending on me!" the priest asserts, upset that he can't reach his congregation. Hawkeye eventually agrees to let Mulcahy hear confessions — through the flap in his tent.

According to the story a source shared with The National Enquirer, Alda himself helped Christopher keep his job by writing the episode just for him. "Alan knew Bill and his wife had an autistic son and his paycheck provided for the boy," the source explained, adding, "Bill recovered from the hepatitis and was eternally grateful to Alan." The actor not only made a triumphant return to form in season 6, but he also got promoted to a series regular spot, and went on to feature in some of the show's most poignant plots. When Christopher passed on New Year's Eve 2016, Alda shared words of kindness about his co-star on Twitter, writing, "His pals from #MASH miss Bill powerfully. His kind strength, his grace and gentle humor weren't acted. They were Bill."