Episode 5 of Big Brother season 27 was released on July 20. It saw another Head of Household, aka HoH, competition, which was won by Jimmy. The houseguests had to find one of the four idols after crawling through mud and looking through packaging boxes. These idols either represented the HoH key or one of the three mystery powers, which included Mystery Competitor, interrogate the HoH, and Mystery Veto.After contestants scrambled to find these idols, Jimmy won the HoH key, Keanu won the Mystery Competitor, while Kelly won the Mystery Veto, and Mickey found the interrogate the HoH key.At the end of the episode, when Jimmy, the new Head of Household, had to nominate three people for elimination, he nominated Kelley, Adrian, and Keanu. He told the former two that he was going to use them as pawns to oust the latter.How Jimmy won the Head of Household in Big Brother season 27 episode 5The new twist, or the Ainsley equivalent of season 27, the Mastermind, again came into play when it came to deciding who was going to be the next Head of Household. After the sounds of red alarms alerted the houseguests, a police bulletin informed them that Mastermind had broken into their house and had stolen the HoH key, along with keys to three other mysterious powers. View this post on Instagram Instagram PostThe contestants were asked to find these keys, but to do that, they needed to cross the black sewers in their way. They first had to crawl through the muddy tunnels of the challenge, then had to go through packaging boxes to find four idols that represented the four keys.At the end of the challenge, it was revealed that Jimmy was the winner of the Head of Household, while Keanu got the Mystery Competitor power. Mickey found the power to interrogate the HoH, while Kelley found a Mystery Veto. The contestants weren't supposed to reveal who won the powers, except, of course, the HoH, because he needed to decide on nominations.What happened after Jimmy bagged the HoH power on Big Brother season 27 episode 5?After Jimmy got the HoH key, the power to nominate people for the Big Brother elimination arena lay in his hands. To be sure about his decision, he went around the house asking people to tell him if they had won anything in the challenge before.Jimmy had an idea about Kelley's veto win because he had seen her taking a veto-shaped idol. Keanu revealed to Kelley that he had won the Mystery Competitor power, which meant that he could bring a former houseguest to compete against someone in the Power of Veto competition. He said he could do this till their season reached pre-jury. View this post on Instagram Instagram PostMeanwhile, Kelley told Jimmy that Keanu knew of her Veto power, but that only meant that she wanted to work with Jimmy and Keanu, to be safe. The Mystery Veto that Kelley possessed gave her the power to rewrite HoH's nominations. However, she could only do this by competing in a solo challenge. Winning this would give her another Veto to save herself or anyone else. This mystery power of hers would activate only after the pre-jury.While Keanu revealed his power to Kelley, Mickey revealed it to Morgan. He told her that he had the power to overthrow and HoH and be one himself. At the end of the Big Brother episode, Jimmy nominated Kelley, Adrian, and Keanu. He wanted to keep the former two as pawns so he could eliminate Keanu.For more updates on Big Brother season 27, fans can follow the show's official Instagram account, @bigbrothercbs.