The NCIS Season 20 finale, "Black Sky," definitely didn't disappoint in terms of suspense and shocking moments. While a major attack on the U.S. loomed in the background, the focus of the episode was on Torres' undercover mission in prison. His goal was to extract information from Yuri, who was believed to be involved in the impending terror attack orchestrated by his father.

Torres faced numerous challenges in prison, especially once Yuri became aware of his presence. Despite Vance's order to withdraw Torres from the mission, he decided to continue, determined to get the information needed. Lev, one of Yuri's men, prompted Torres to provide basic information for a background check, which raised concerns among the team about his cover story.

However, Torres adeptly covered his tracks with the help of Kasie.

Meanwhile, the team struck a deal with Russian spy Evelyn, offering witness protection in exchange for vital information. McGee managed to crack the code used in Yuri's texts with his father, revealing their plan to target the U.S. power grid. The attack would lead to widespread electricity outages that could potentially cripple the country for weeks or even months.

As Torres gained Yuri's trust, he learned about his troubled relationship with his sister. However, things took a dark turn when Boris and Lev turned on Yuri, leading to his untimely demise.

Torres was then pulled from the mission, and Lev was taken into custody. Torres realized that Yuri's father had ordered the hit on his own son to protect his plan.

During Lev's interrogation, he requested a lawyer just as Parker arrived, pretending to be his attorney. Parker intercepted a message from Yuri's father, which mentioned a Dodge Challenger with a specific license plate number. The agents discovered that this was actually a plane that had recently left Russia and was likely transporting Yuri's father to the U.S.

However, just as the team made this breakthrough, a massive power outage occurred across key cities, signaling a computer virus attack.

With communication systems down, the team resorted to using walkie talkies. Torres remembered something significant that Yuri had said about his sister, and they connected the dots to discover that she was behind the cyber attack. They apprehended her and managed to restore power with the assistance of McGee and white hat hackers.

Back at the prison, Torres encountered another inmate, a teenager who claimed to have been framed for fraud. Torres noticed a suspicious man visiting the teenager and began to suspect that he was involved in the conspiracy. Returning to NCIS, Torres left an urgent voicemail for his sister revealing that he had found the man they had been searching for.

He hinted that their lives were still in danger.

In a shocking twist, instead of resting at home as he had suggested earlier, Torres awaited the man's arrival and confronted him. It became clear that Torres harbored deep resentment for this man, and he revealed his intention to witness his death. The season concluded with this chilling cliffhanger, leaving viewers wondering about Torres' next move.

Overall, the Season 20 finale of NCIS packed a punch with its intense undercover mission, revelations about the terrorist plot, and the unexpected storyline involving Torres. The episode ended with a tantalizing hint of what's to come in Season 21.