The Hot Zone limited drama series about the Ebola virus starring Julianna Margulies drew record ratings for National Geographic, becoming the network’s most-watched scripted series of all time. The Hot Zone averaged a .82 in Live+3 ratings in the demo over three nights, besting previous record holder Genius: Einstein, according to Nielsen. It also was just shy of besting The Story of God With Morgan Freeman as the network’s most-watched series of all time, and making it the second-most-watched scripted series to premiere on ad-supported cable so far this year.

The Hot Zone boosted National Geographic’s viewership 350 percent above the previous six-week average in prime time. The May 27 series premiere also lifted Nat Geo to the No. 5 ad-supported cable network in the target demo for the night and No. 2 among total viewers.

Across 12 broadcasts through the May 29 finale (premieres and repeats), the series was viewed by 7.5 million people in the U.S according to the network and Nielsen. The Hot Zone will begin airing in 172 countries and in 43 languages throughout the summer.

Based on Richard Preston’s best-selling book of the same name, The Hot Zone is inspired by the true events surrounding the origins of the Ebola virus and its arrival on U.S. soil in 1989. Margulies, Noah Emmerich, Liam Cunningham and Topher Grace lead the ensemble cast. In The Hot Zone, a heroic U.S. Army scientist, Nancy Jaax (Margulies), working with a secret specialized military team, puts her life on the line to head off the outbreak before it spreads to the human population.

The Hot Zone is a co-production of Fox 21 Television Studios and Scott Free Productions.