WARNING: This article contains spoilers for Chernobyl on HBO that may influence your enjoyment in discovering the plotlines. Read at your own risk.

Ulana Khomyuk (played by Emily Watson) demands someone in Russia, to tell the truth about the nuclear explosion in Chernobyl episode 4. The miniseries which airs on HBO will air its penultimate episode on Monday, May 27, at 9:00 p.m.

Khomyuk is seen in the teaser of Chernobyl episode 4 convincing Anatoly Dyatlov that someone has to tell the world the truth about the accident at the nuclear plant. He was one of the officials who has been in absolute denial about the explosion of the nuclear reactor that had a catastrophic effect on humans. 

While Khomyuk has been talking to the survivors to uncover the events of the explosion, Valery Legasov (played by Jared Harris) and Soviet Deputy Prime Minister Boris Shcherbina (played by Stellan Skarsgård) discuss bringing in lunar rovers to take out the radioactive debris, as per the episode synopsis.

In an earlier episode, Legasov and Shcherbina succeeded in averting another catastrophe to decontaminate the nuclear site. The exposed reactor was still at risk of exploding underground and pollute the rivers nearby, which would devastate the whole continent permanently. 

As per the Chernobyl Gallery, lunar rovers were indeed used to clear out 200 tons of radioactive wastes scattered all over the plant. This incident, which happened in April 1986, is still the subject of much debate today because of the number of victims affected.  

Those who were on the scene either burned and died within weeks of the disaster, while residents within the explosion's radius continued to suffer various diseases even today, such as cancer or deformities in the cases of newborn babies. Officials of the Soviet Union at that time were accused of doing a massive cover-up and not listening to the experts, as seen in the miniseries.

"It's a very cautionary tale for our times, this piece," Watson said of her show in an interview with Collider. "We're not living in a totalitarian state, but we are living in a place where the truth is not fixed, and the goal posts are shifting, as far as what truth is and who owns it." 

Chernobyl filmed for five months in Lithuania under the direction of Johan Renck. The show has five episodes only and has been planned as a one-season series. 

This production is a joint project between HBO in the U.S. and Sky in the U.K. for $250 million. Chernobyl is written by Craig Mazin.