Rosarito was home to nearly 65,000 people at the time of the outbreak. The city bustling with tourists, including Americans celebrating a wedding, and the popular Rosarito Beach Hotel was at full capacity. Like in many other cities, rumors of the sickness were rampant, sparking some fear among residents. While Mr. and Mrs. Stowe were aware of the rumors regarding the government wanting to closing the border, Elena tried to calm their fears, reducing them to Internet gossip, but Elena herself was aware of the potential threat behind the sickness.
After the outbreak ravaged the city, most of the population was killed off and the city remains abandoned, though fires can be seen burning out of control throughout the city.
After spending two days searching for Nick, Strand drives the group back to a rocky beach in Rosarito to board their yacht. However, after finding it stolen, Alicia suggests they head into the city and set up camp in the large hotel on the beach.
Parking on the beach, they observe the hotel from the outside but do not witness any signs of life. They enter the lobby after forcing their way inside, acknowledging that someone had already locked down the hotel. After sweeping the ground floor, including the kitchen, Madison and Strand decide to stay behind at the bar while Alicia and Ofelia begin searching some of the upper floors of the tower. They find several rooms with "Do Not Disturb" signs on the doors, indicating that zombies were locked inside. As they scavenge, they find food and clean clothes as well as hot water in the showers. Meanwhile at the bar, Madison and Strand get drunk and begin playing the piano, drawing zombies to their location while Ofelia goes missing and Alicia becomes trapped on her floor after zombies fill the stairwells.
It is revealed that the Rosarito Beach Hotel was at full capacity with guests and was holding a wedding party in the ballroom at the time of the outbreak. After the bride is attacked when her father dies of a heart attack and reanimates, the hotel manager locks everyone in the ballroom to contain the situation, creating a bloodbath for the dozens of people trapped inside.
About a month later, it is revealed that hotel manager Elena Reyes and her nephew Hector, a waiter, have been living in the tower. Also residing in the hotel are several surviving wedding guests, including the groom Oscar, his brother Andrés, and the mother of the bride Ilene, among others.