Sonny has a one-night-stand with Claudia after being dumped by his ex-fiancé Kate Howard. Sonny and Claudia decide to keep their names a secret but over time, Claudia's identity is discovered and then when Claudia is turned down many times by Sonny, she devises a plan to kill him. Michael being shot by Ian Devlin, which was ordered by Claudia, forces Sonny to quit the business, fearing for the people he loves. Claudia makes it simple that she wants Sonny to pay for hurting her. No one knows that Claudia is the one behind it expect for Nikolas. Claudia feels really guilty.
Marriage
Anthony makes a deal with Sonny after Kate is shot. The deal is that Sonny marries Claudia to join the Zacchara Empire. Although Sonny turns down the offer, as the situation gets worse, he agrees. Sonny doesn't know that Anthony was the one that shot his love. Claudia and Sonny get married in December.
Sonny has completely taken control of the Zacchara organization as the head of the family. Sonny has told Claudia and Ric that he doesn't want them to have their affair, so Claudia breaks up with Ric. Sonny learns that Jason's biological son is kidnapped but is refusing to help him because he is now an enemy. Sonny is yet to tell Morgan and Kristina of their new step-mother. Sonny doesn't see Morgan because of the custody agreement that Carly forced him to sign, but due to the holiday season, Carly reconsiders and Morgan and Sonny see each other occasionally.
Jerry Jacks sends Claudia DVDs to find in the Corinthos Mansion. The DVDs reveal that she was responsible for Michael's shooting. Claudia succeeds in finding most of the DVDs, but Kate Howard succeeds in finding one and is now in the loop of the Corinthos shooting.
Claudia and Sonny are invited to the Michael Corinthos Wing opening at General Hospital's Board Room when biotoxin is released in the air. The event is held by Carly Jacks and Kate arrives to tell Sonny the truth about Claudia's involvement in Michael's shooting. In those moments, Kate collapses and moments later, Claudia collapses. Sonny worries about Claudia's safety when the hospital is burning to the ground. Sonny then learns from Claudia that Anthony was the one who shot Kate and was planning on killing him and Jason Morgan. Claudia teams up with Corinthos, but Anthony escapes.
When the hospital is completely evacuated, Sonny catches Kate harassing Claudia. Sonny defends Claudia over Kate and the two share dinner. Sonny, Claudia, Spinelli, Sam, and Jason are now out to find Anthony Zacchara.
While everyone thinks Anthony is in Florida, Anthony is actually in Port Charles and now has Claudia hostage until Sonny arranges 21 million dollars in a wire transfer. Sonny finds Claudia tied to a bomb and he dismantles the bomb. When they arrive home, Claudia kisses Sonny and she admits that she is falling in love with him and they make love. Claudia later visits Michael (impersonating Monica Quartermaine) and confesses that she is the reason he is comatose. Sonny confides in Claudia that he wishes there could be a way to revive Michael without getting his and Carly's hopes up. While Claudia is distracted by Sonny, Carly, and Michael's condition, Ric lands his hands on one of Jerry's incriminating DVDs, and so does Jax. Sonny decides to hold a mob party to show everyone in the business that he is boss. He is, however, also forced to allow Ric Lansing in the business due to his wife's demand. Ric blackmails Claudia with one of Jerry's DVDs. Sonny confronts Claudia in her bedroom. Little does he know that his wife has drugged Ric Lansing and has almost killed him.
Sonny has now asked Jason to help him find out who else was involved in Michael's Shooting. In a desperate effort to survive, Claudia now has a plan to stay alive and stay married to Sonny. Claudia plans on getting pregnant unbeknownst to Sonny. Michael recovers from his coma and Claudia tells him about her pregnancy. The two get really close, which causes Michael's mother Carly to try and get rid of Claudia. Carly and Claudia get into a confrontation on the hospital stairs, which threatens Claudia's pregnancy and with Ric on her case. Sonny is suspicious of Claudia and Ric and then throws Claudia out of his house. After months of speculation, Claudia has her amnio, revealing Sonny is the father of her unborn son. On the way to tell him, she is hit by Kristina Corinthos-Davis and has a miscarriage. Sonny, who was having an affair with Olivia Falconeri, ends his trysts and reconciles with Claudia. Claudia and Sonny begin to get along and eventually Claudia agrees to forgive Kristina.
Claudia's death
After Claudia impresses Sonny by handling rival mob bosses with finesse, he decides to throw a birthday bash for her. In the days before the party, Sam McCall and Jason Morgan get proof that Claudia was responsible for Michael's shooting and they tell Sonny right before the party. After finding out the truth about Claudia's involvement in his son's shooting, Sonny makes a toast to her, calling her out for all the wrongs she has done. Claudia grabs a very pregnant Carly and kidnaps her at gunpoint. Claudia steals a car as Carly goes into labor. Carly grabs the steering wheel and causes the car to crash. Claudia is unconscious and Carly escapes the car uninjured and makes her way through the woods to a cabin where she prepares to deliver her baby on her own. Claudia then shows up and delivers baby Josslyn. Claudia has lost her grip on reality at this point and believes that Josslyn is her baby. She puts Josslyn in a basket and starts to go toward the door with her. Carly is too weak to get up and stop her. At that moment, Michael walks through the door. He had found the crashed car and heard Carly's pleas for Claudia to leave Josslyn. Seeing that Claudia is kidnapping his newborn sister, Michael grabs the first thing he sees, an axe handle, and hits Claudia in the head with it, making her drop the basket with Josslyn inside, and killing Claudia.
