Antonio is going to Puerto Rico with Sonia. Bo feels he is walking into a trap. John and Bo want to give him back up, but they don't have enough time. Evangeline and John talk about their night together. They agree that due to the wine and confined space they got sidetracked. R.J. asks Evangeline if she is having an affair with John. Evangeline refuses to answer. R.J. hires someone to follow Evangeline. Antonio suggests to Bo that he work on the back up while Antonio is on the plane to Puerto Rico. Jessica uses Antonio's computer and discovers he is going to Puerto Rico and not Atlanta, which was what he told her when she asked. Sonia reveals to Antonio that she kidnapped Adriana until Antonio's identity and agenda is verified.
Jessica is afraid that Paul could get Natalie killed. David brings Paul at gunpoint to Dorian's house. Dorian also pulls a gun on Paul and demands that he tell her what he was looking for in her house when Blair found him. Paul reveals to Dorian that he has a map to the vault and two thirds of the combination to it. He promise to give them a fifty fifty split. Jessica makes a rough sketch of the map to the Santi vault that was laying on Natalie's table. Dorian and David catch Paul and Natalie trying to leave town without them.
Nora may have been infected with the mystery virus going around. Bo and Nora are quarantined until further notice from the Department of Health.
Nigel is held at gunpoint by Carlos. Carlos tells Nigel to call Mary Barnes room. Nigel calls John instead. John rescues Nigel from Carlos. Carlos won't give up any information.
John fills in Evangeline on Carlos' arrest. John realizes they are being followed. He informs Evangeline, who immediately kisses John. Evangeline figured out that R.J. was having her followed. R.J. confronts Evangeline about the kiss and asks again if she is sleeping with John. Evangeline tells him he does not deserve the truth. Evangeline and R.J. break up. Evangeline invites John to dinner. John interferes when R.J. tries to talk to Evangeline. R.J. has plans for John. John asks Carlotta about Adriana. Carlotta reluctantly tells him Adriana should be at work.
Riley and Jen talk about their friendship. They decide to keep it platonic. Rex tells Shannon to keep her eyes on the prize (River) and not let anyone screw with her. Roxy takes a brewski break with the gang. Marcie wants to lose weight because of Nick's snide remarks, but Jen feel Marcie looks good the way she is. River and Shannon kiss.
Blair doesn't like the idea of Todd pretending he is Ace's father. Blair urges Todd not to get mixed up into Kelly's mess. Blair has a dream that Kelly took Starr and Jack. Blair wants to protect Todd and Ace from Kelly's lies.
Margaret plots revenge on Kevin by messing with B.E. finances. Kelly leaves a note for Kevin under his office door. Margaret gets a hold of the note. Kevin gets Todd's blood type. Magaret reads Kelly's note to Kevin. The note says, " You are not Ace's father, Todd Manning is." Kevin finds the cufflink with Todd's initials on his office floor, the one Margaret planted. Kevin now suspects Todd messed with the company's finances. Kevin shows Blair the note. Blair is not surprised. Kevin suspects Todd told her he is Ace's father. Blair denies that Todd is Ace's father and says Kelly is not telling the truth. Margaret sees Todd and Kelly with Ace. She plans to get the baby in order to get Todd.
John continues his search for Adriana, stopping at the diner to ask Carlotta if she knows where Adriana is. Carlotta believes that she's staying with Dorian, but Dorian is away on a trip and a check with the day care where Adriana works informs him that she hasn't been seen there in days. In fact, no one has seen her since the night of the 4th of July. John tracks down Rex, who was the last person to be seen with her. After some pressure by John, he admits that he and Shannon are trying to break Adriana and River because Shannon is interested in River. He is forced to admit in front of Lindsay, who had come looking for him when he didn't show up to work at Ultra Violet, that he was involved because he was interested in Adriana. John calls Bo to give him an update. Bo suggests he check with Jen because he saw her filming the night of the 4th of July. John heads back to the diner and asks Jen if he can check the tape to see if there are any clues about Adriana.
At the diner, Jen and Riley have a discussion about whether to take their relationship "to the next level." They almost kiss, but ultimately decide they don't want to risk losing each other's friendship by getting romantically involved. Neither of them looks particularly happy about the decision.
Quarantined in Nora's house, Bo and Nora are extremely cranky and get into an argument, which upsets Matthew. They claim they are arguing because they are not feeling well, but Matthew thinks it has more to do with Bo being jealous of Daniel's relationship with Nora. After playing some board games, Bo and Nora both fall asleep on the couch. Matthew grabs a blanket and crawls up on the couch between his parents to go to sleep.
In Puerto Rico, Antonio comes face to face with the acting head of the Santi crime family. He is very suspicious of Antonio, especially since he used to be a cop. He also asks Antonio if Tico sent him, but Antonio replies that he's never even met his cousin Tico. Handing Antonio a gun, Antonio is asked to prove his loyalty by shooting Sonia.
David, Dorian, Natalie and Paul arrive in Puerto Rico and head out in search of the Santi money. But thanks to Jessica's false instructions that everything on the map is reversed, they waste the day wandering around the mountains. John calls Dorian to check if Adriana is with her. Once Dorian finds out that Adriana is missing, she decides to fly home to Llanview immediately.
In the meantime, Jessica is also in Puerto Rico and calls on one of Antonio's friends in the police department for help. He warns her that if Antonio is trying to infiltrate the Santi crime family, he is in great danger and will probably not make it back alive. Jessica frantically calls Carlotta and asks her for the numbers from the broach, which will complete the combination for the vault. She has heard they sometimes lock traitors in the vault and is worried for Antonio's safety. Carlotta gives her the numbers and Jessica and the police officer find the vault and begin to open it. The police officer leaves to go get some backup. Jessica enters the vault and finds a man being held prisoner there, but it is not Antonio.
Jessica frees the man from the vault and rushes him to the hospital to be checked out. There, she learns that he is Manuel Santi's son, Tico, and that he was left there to die.
Meanwhile, Antonio shoots the Santi bodyguard in self-defense while Sonia kills the Santi boss.
David, Paul and Natalie make it to the vault. While the FBI nabs David and Paul, Natalie sneaks off. As Kevin shocks Viki with the news that Todd is Ace's father, Blair has an all-out brawl with Kelly.
Evangeline warns Todd that Kevin is out for his blood. Blair tells Kevin that neither he nor Todd is Ace's father, which Kevin refuses to believe. Fed up with her lies, Kevin files for a divorce from Kelly.
The bickering at Nora's house continues, to the point where they actually create a line down the center of the house and create a schedule for time to spend in the kitchen. Matthew unhappily watches his parents snipe at each other about their lack of cooking skills. When Evangeline stops by to drop off a file, Bo refuses to take it and sends her around to the side door, which is in Nora's part of the house. They are both thrilled when Jordan arrives to examine them and tells them the quarantine is over. Bo rushes off to work, but returns later to get his cell phone. Matthew invites him to stay for movie and a pizza and he agrees, settling down on the couch next to Nora. When the phone rings, Matthew answers it and lies to Daniel, saying his parents are still under quarantine.
There's even more bickering at the house where the students are staying, all of them are unhappy with their current roommates. Roxy comes up with the idea of changing roommates and puts Jen and Riley together and Marcie and Shannon become roommates, too. Nick invites Jen to go to Ultra Violet. She agrees, as long as Marcie comes with them. Riley refuses to go, but seems jealous that Jen is going with Nick. After they leave, Mark tells Riley that he should admit to himself that he wants Jen.
Dorian and Carlotta pay John a visit at the police station and inform him that Adriana is safe and sound at the convent school. They return to the diner and worry about the possible danger that Antonio, Adriana and David are in. Evangeline visits John and learns that the person who killed Kathryn and the accountant killed himself with a cyanide pill rather than divulge any information about the person who hired him. Unable to get in touch with Antonio, John decides he needs to go to Puerto Rico and see what's going on for himself.
In Puerto Rico, Antonio sends Sonia to talk to her contacts and get some information about what is going on. He takes the opportunity to talk to his police friend and finds out that Jessica is in Puerto Rico and that she is at the hospital with the man that they found in the empty Santi vault. Antonio also learns that Paul and David are currently in police custody. Sonia returns and catches them talking, but Antonio tells her they used to work together and just happened to run into each other. Later, Sonia almost sees John when he arrives at the hotel in Puerto Rico, but Antonio kisses her to distract her. When Sonia leaves, Antonio catches John up on what has been going on, including the death of the Santi second in command. John wants Antonio to end the undercover operation now, but Antonio refuses, Sonia is hiding something and he is determined to find out what it is. Sonia returns and from a distance sees the two of them together. She pulls out her gun, but John spots her and pushes Antonio to the ground, pretending to arrest him.