“Chernobyl” has just ended its run on HBO as the highest audience-rated TV series in history. An expansive miniseries that narrates the story of the Chernobyl nuclear disaster, “Chernobyl” has been a magnet for history buffs since its premiere. Interestingly, each episode title of this series represents key moments during the actual Chernobyl disaster.

The goal of the miniseries is to tell everything that happened during the 1986 disaster at the Chernobyl Nuclear Power Plant over the course of five intense episodes. Although the story was partly altered, “Chernobyl” accurately presents the events as they happened at the time, with all the crucial details spread throughout the five episodes. Here are the episode titles of the miniseries and what they actually signify.

Episode 1: “1:23:45”

This was the exact time of the explosion of reactor 4 at the Chernobyl Nuclear Power Plant. At this time in the morning of April 26, 1986, the fatal disaster took place.

Episode 2: “Please Remain Calm”

This phrase played from the loudspeakers stationed on top of the military vehicles in Pripyat after the need to evacuate was announced to the public. It intended to keep the people of Chernobyl calm amid the disaster.

Episode 3: “Open Wide, O Earth”

The final scene in this particular episode ends with the burial of Vasily Ignatenko. In the Christian world, particularly in the Eastern Orthodox Church, burials are accompanied by a hymn that opens with the line “Open wide, O earth.” This hymn is usually being played as the body of the deceased is pulled down the ground.

Episode 4: “The Happiness Of All Mankind”

Around the time of the Chernobyl disaster, the Soviet Union got so obsessed with propaganda and were hiding secrets from the public. Because of this, there was a point when banners were hung in local villages, bearing the phrase “For the happiness of all mankind.”

Episode 5: “Vichnaya Pamyat”

This episode title takes the same inspiration from episode 3’s title. “Vichnaya Pamyat” was taken from another burial ritual of the Eastern Orthodox Church, in which the choir sings “Vyechnaya Pamyat” thrice at the end of the church ceremony. This phrase means “memory eternal.”

'Chernobyl' 'Chernobyl' airs Monday nights on HBO. Facebook/chernobylminiseries