At age 14, Juan Carlos Renato Ruiz de Vasquez stumbled upon a man named Sergio attempting to rape a young woman working on his family's ranch. During an altercation, Carlos killed Sergio and Sergio's gang vowed revenge on Carlos. Carlos was forced to flee Argentina and ended up in Philadelphia. No one knew where Carlos had landed, not even his family. And no one knew the secret that Carlos was keeping.

Flash forward to 2003 where Carlos, working as a handyman at Fusion Cosmetics, was immediately attracted to Greenlee, even though she was from a richer crowd and enjoyed being rude to him on a daily basis. Greenlee started getting anonymous emails with romantic poems and words that began to warm her heart, and her attitude towards Carlos. They decided to try to build a respect and a friendship for each other. Little did Greenlee know that Carlos was her secret admirer and was having his sister write those mushy words. After Greenlee saw Carlos smelling and holding a scarf of hers, she thought that he might be the one sending her emails. Greenlee decided to invite him over to her penthouse by lying about a broken pipe. When Carlos arrived that evening, he told her that he was the one sending her the sweet emails, but didn't reveal more than that.

Greenlee and Carlos grew closer. Greenlee was able to look past the fact that he was a "handyman" and didn't come from a wealthier class. She even went to him with a bar to meet his wild, rowdy friends and where he sang to her in Spanish. Things started to go sour when Greenlee found out Carlos wasn't the one writing the emails. She told him she couldn't trust him anymore and he wasn't who she thought he was. Carlos and Greenlee made amends later, and decided to give their romance another try.

However, it ended when Greenlee used information he had given her about Mrs. Lacey, the owner of Lacey's department store, to land Fusion counter space. Thanks to Greenlee making Carlos look like he had broken Mrs. Lacey's trust, Fusion knocked out Enchantment's counter space, and got their own. After Simone accidentally blurted out Greenlee's scheme, Carlos confronted her at The Valley Inn, where their romantic evening turned bleak. Greenlee admitted what she did, but wasn't sorry for it. Carlos stormed out of the room and told Greenlee it was over; he quit working at Fusion and went to work for Stuart at his art gallery, where he could also sell his own art. Soon after their relationship ended, a mysterious stranger came to Pine Valley named Juan Pablo. He showed interest in Fusion and all the Fusion ladies. Mia, Liza, Greenlee, Kendall, and Simone were all wooed by his demeanor, but Tad wasn't so sure. He thought that it was more than a miracle that Juan Pablo showed interest in all of the Fusion ladies. After Tad Martin did some investigating, he blew Juan Pablo's cover.

Turned out, Juan Pablo and Carlos were really brothers! Juan Pablo came to Pine Valley to protect Carlos from an Argentina mob, looking to seek revenge on him. In an heroic act, Carlos saved a woman who was almost raped, but the rapist did not survive. Carlos didn't mean to murder the man, but he wasn't going to let the man harm this woman.

When Greenlee found out about Carlos secret, she realized that they both kept secrets from each other. They agreed to call it truce. However, the relationship between Greenlee and Juan Pablo only got better and more passionate. Carlos asked Juan Pablo if he really cared about Greenlee, or if she was another one of his short-lived conquests. Juan Pablo claimed that he truly cared about Greenlee and he wasn't going to do anything to harm her. With that said, Carlos hugged his brother and gave him his blessing.

Sergio's gang of mobsters descended into Pine Valley, looking hungrily for Carlos. Juan Pablo and Carlos decided it wasn't safe for them to stay in Pine Valley and made arrangements to fly out. Juan Pablo told a heartbroken Greenlee that their relationship was nothing more than a fling, in order to protect her from the mob. Of course, Greenlee wasn't satisfied with his excuse and followed Carlos to a deserted alley one night looking for answers. Carlos saw headlights coming straight for them and threw himself in front of Greenlee. The driver was an old man who suffered minor injuries and claimed that he didn't see them because of the dark. Thanks to Carlos' heroic act, Greenlee was spared, while Carlos was crushed under the car. Ryan Lavery found Greenlee unconscious on the street and called the paramedics, who rushed them to the hospital.

Greenlee sustained a short memory loss once she woke up from a coma, but it didn't last long, and she was unharmed. Carlos, on the other hand, was not as lucky. Besides broken bones, he was suffering internal injuries and remained unconscious. Juan Pablo and Carlo's doctor, Maria Grey put Carlo's in a secret ward of the hospital and had cops monitoring his visitors to protect him. The old man who hit Carlos and Greenlee stopped by the hospital with his grandson. The old man was in a wheelchair with a blanket tucked under his lap. The grandson asked Juan Pablo if his grandfather could go in and say a blessing for Carlos. Juan Pablo let them go inside after the old man explained how awful he felt for running over Carlos and Greenlee. When Juan Pablo followed them inside, he overheard the grandson say something to his grandfather in Spanish! Juan Pablo immediately figured out that they were part of the mob, tackled the grandson, and found a gun hidden under the grandfather's blanket! Both men were dragged out by the cops.

After that incident, Juan Pablo knew that he had to get out of Pine Valley with Carlos fast. He asked Maria to relocate his brother to another hospital, but she refused. She thought it was too risky to move him, but if he got better and stronger, she would relocate him to wherever Juan Pablo wanted. Shortly after, Carlos went through an operation that saved his life. Maria told Juan Pablo that Carlos could move to another hospital. While Carlos was recovering, Juan Pablo started making plans to leave Pine Valley with his brother.

During a visit by Simone Torres, Carlos started having trouble breathing and Simone rushed out of his room to get Maria. The doctors rushed in and started pumping his heart, but they were unable to save him. Juan Pablo was devastated when Carlos died. Before his death, Carlos was recovering so well and when Juan Pablo sought answers from Maria, she wasn't able to give him any. Juan Pablo blamed Maria for Carlos' death. Maria went through all of Carlos' medical records and X-rays until she stumbled upon a bone fragment she missed in the surgery. She felt guilty and believed Juan Pablo, until her husband, Edmund, proved him wrong.

After some investigative research, Edmund discovered that one of the male resident nurses was connected to the mob by a gold ring he wore on his finger. The nurse had implanted the extra bone fragment and murdered Carlos! Juan Pablo, Edmund, and Aidan Devane persuaded the nurse to give them the information they wanted. Juan Pablo began his search for the mob and justice for Carlo's murder.