On Day 1, Alison, Dana, David, Erika, Jack, Jun, Nathan, and Scott entered the Big Brother House. Upon getting to know one another, they competed in the "X Marks the Spot" food competition, in which everyone successfully earned food for the first week. Upon returning inside, they were informed of the X-Factor twist, in which five more HouseGuests would be entering the game, and would be exes of some of the eight already in the house. Following this announcement, Amanda, Jee, Justin, Michelle, and Robert entered the House. On Day 3, HouseGuests partnered up and competed in the "Who's Ya Chum?" Head of Household competition. Though Alison and Nathan won the endurance portion of the competition, Scott chose which of the two would become the first HoH; he chose Nathan. On Day 5, he nominated Amanda and Jee for eviction. On Day 7, Dana won the "Feeling Knotty" Power of Veto competition and chose to keep nominations the same. On Day 8, Scott was expelled from the game after a violent outburst in which he revealed he had a sexually transmitted disease. On Day 12, Amanda was evicted in a unanimous vote. Following Amanda's eviction, the remaining HouseGuests competed in the "Majority Rules" HoH competition, in which they had to answer questions on how they felt the majority of the HouseGuests would vote. Jee was the winner of the competition. The following day, Michelle, David, Robert, Dana, and Nathan were put on the peanut butter and jelly diet after losing the "Clash of the Casseroles" food competition. Jee nominated Erika and Michelle for eviction on Day 13. On Day 14, David won the "Duck Ball" competition and chose to leave the nominations the same. On Day 19, Michelle was evicted in a six-to-two vote, only receiving the votes of Justin and Robert. Following Michelle's eviction, HouseGuests competed in the "Everything In Three's" Head of Household competition, in which they faced off three at a time answering questions. Dana was the winner of the competition. On Day 20, all of the HouseGuests earned food for the week after the "Paratrooper" competition, in which they had to catch falling commando dolls in military hats. Each doll had the name of a food on it and if they got the doll they earned that food for the week. Later that day, Dana nominated Alison and Jack for eviction. The following day, Nathan won the Power of Veto and used it on Alison. David was named as her replacement nominee. On Day 22, Alison won the "Spin-O-Matic" luxury competition, earning her and another HouseGuest a luxury dinner. She chose to take Nathan with her. On Day 26, David was evicted in a five-to-two vote, only receiving the votes of Erika and Alison. Following David's eviction, Alison won "Around the Water Cooler", in which HouseGuests had one minute to stack as many cans as possible by dropping them into a tube. Dana, Erika, Jee, and Robert were put on the peanut butter and jelly diet after losing the "Laying Pipe" food competition. Alison chose to nominate Dana and Jun for eviction. On Day 28, Robert won the "Snake In the Grass" Veto competition and chose to leave the nominations the same. On Day 33, Dana was evicted in a unanimous vote and become the first HouseGuest to enter sequester. Following Dana's eviction, HouseGuests competed in the "Who Said It?" Head of Household competition, in which HouseGuests tried to guess which evicted HouseGuest made a certain statement while in the house. Justin won the competition. The following day, everyone earned food for the week during the "50 Ways to Cook a HouseGuest" food competition. Justin nominated Jack and Nathan for eviction. On Day 36, Robert won the "Quoridor" Power of Veto competition and chose not to use the Veto on either Jack or Nathan. On Day 40, Nathan was evicted in a unanimous vote, becoming the second member of the jury. Following Nathan's eviction, HouseGuests competed in the "Steel Cage Match" endurance Head of Household competition, in which HouseGuests had to stay inside a steel cage, and were eliminated if they left. Erika won the competition. The following day, everyone earned food for five out of the seven days after the "Clambake From Hell" competition, as Justin and Alison were unable to complete their dishes in the allotted time. Erika nominated Justin and Robert for eviction later that day. On Day 43, Jun won the "Video Veto" Power of Veto competition and chose to leave nominations the same. On Day 47, Justin was evicted in a three-to-one vote, only receiving the vote of Jee. Following Justin's eviction, HouseGuests competed in the "Black HoHle" Head of Household competition. Jee was the winner of the competition. He nominated Erika and Jack for eviction. The following day, Jee won the Power of Veto after forcing the other HouseGuests on the peanut butter and jelly diet for the week. He chose not to use the Power of Veto, leaving his nominations intact. Marcellas from Big Brother 3 returned briefly for a competition filled with gnomes where the winner would receive five McDonalds meals a day with one other houseguest of his/her choice. Jee won the task and chose Jack to join him. Despite Jee wanting Erika evicted that week, Jack was evicted in a two-to-one vote, only receiving the vote of Robert. Following Jack's eviction, HouseGuests competed in the "Disappearing Act" Head of Household competition, which Jun won. Jun, as HoH, won a special trip outside of the
Big Brother House to attend the 20th Annual
MTV Video Music Awards. Her disappearance (as she entered the Diary Room and never returned) played a part in the Veto competition, as the HouseGuests had to guess where Jun was. Jun returned and nominated Jee and Alison. However, Alison won the Veto and used it on herself, forcing Jun to put Robert in her place. Despite Robert being a replacement for Alison, Jee was unanimously evicted. Following Jee's eviction, Robert won the "Dearly Departed" Head of Household competition. The following day, everyone earned food during the "Mexotic Dinner" food competition. Robert chose to nominate Alison and Jun for eviction. The following day, Alison won the Diamond Power of Veto, which was the final Veto competition of the season. Alison removed herself from the block and Erika was named as her replacement. Alison then cast the sole vote against Erika on Day 68. The final Head of Household competition occurred in three parts. Alison won the first round, the endurance "On the House" competition. In the second part, Jun beat Robert in the "Unexpected Relations" competition, a challenge based on events that had taken place in the house. Alison and Jun then faced off in the Final Round of the HoH. After eight questions based on their ex-boyfriends Jee and Justin, the women were tied on four correct answers apiece. The tiebreaker question was "How many days did you date your ex for?", to which Alison answered zero days and Jun answered one million. Therefore, Alison emerged as the final Head of Household for the season and chose to evict Robert. On Day 82, Jun was crowned the winner of Big Brother 4 in a six-to-one vote, with Alison only receiving the vote of Nathan. ==Episodes==