A talented doctor who liked to surf and had a passion for saving the planet, Dr. Daniel Jonas was instrumental in getting a hospital in Switzerland to "go green."
The early history of Daniel Jonas was not shown on screen, but told through stories. Before coming to Salem, Daniel worked as a doctor for various hospitals around the world. While working at one hospital, he met and fell in love with a cancer patient named Rebecca. Although he knew that her diagnosis was grim, Daniel married Rebecca and was determined to save her. However, her cancer was too much and she died in Daniel's arms. Since her death, Daniel traveled the world, not staying in any place for too long.
In March 2008, Victor brought his godson, Dr. Daniel Jonas, to Salem to help diagnose and treat Bo's mysterious pancreas disease. Daniel saved Bo's life by performing a live donor transplant. In this case, the live donor was Bo's daughter, Chelsea. After the successful surgery, Lexie offered Daniel a permanent job with Salem University Hospital, and he accepted.
Despite their age difference, Chelsea quickly began to take a romantic interest in Daniel. But, Daniel was not interested in a relationship-- with Chelsea or anyone else-- due to his experience with Rebecca. However, Daniel found it hard to ignore his feelings for Chelsea. Soon, he gave in and the two started dating.
Bo and the rest of the Bradys made peace with Daniel and Chelsea's age difference, when viewers learned that Daniel and Kate had a brief but passionate affair when Daniel was Chelsea's doctor. Daniel and Kate both maintained that Chelsea must never find out about them. But she did find out when she saw a text message from Kate on Daniel's phone. She dumped Daniel and was furious with Kate.
When Chelsea dumped him, Daniel picked up his flirtation with Kate. The two became close again, and even closer when Daniel diagnosed Kate with lung cancer. Daniel worked hard to cure Kate's cancer, even performing a radical bone marrow transplant with Chloe as the donor. As Kate began to heal, Daniel developed feelings for Chloe. Despite the fact that Chloe was engaged to Lucas, Daniel had fantasies about making love to Chloe. The two tried to fight off their attraction. When Kate broke things off with Daniel, he started pressuring Chloe to break things off with Lucas so that they could be together. At first, she refused, but on the day after her engagement party, Chloe and Daniel made love.
Daniel and Chloe couldn't stay away from each other, despite the fact that Chloe did go through with her marriage to Lucas. Kate caught Daniel and Chloe together in the park and was furious. She poisoned Chloe and set Daniel up to take the fall- complete with planted finger prints on the bottle of poison in Daniel's apartment. Chloe fell into a coma. Daniel was arrested for the crime.
Once out on bail, Daniel fought to save Chloe. He snuck into her hospital room to administer a life saving drug. When Chloe woke up, she confirmed Daniel's story that the two of them were in love and the charges against Daniel were dropped. Daniel and Chloe got engaged and prepared to start a family.
Little did Daniel know that he already had family in Salem - a daughter. Carly returned to Salem in the fall of 2009 with a secret, which soon came out. Thanks to a one-night stand, Daniel was Melanie Layton's biological father. When the news came out, Daniel set out to get to know his new daughter.
While Daniel and Melanie built a relationship, Daniel's relationship with Chloe ran into trouble. Mistakenly thinking that Daniel was sleeping with Carly, Chloe had a one night stand with Philip. To complicate matters, a few weeks later Chloe found out that she was pregnant. Daniel was thrilled. Chloe worried that the baby might not be Daniel's. So, she got a paternity test. The results showed Daniel to be the baby's father.
Never knowing that the baby might not be his, Daniel pushed forward with the wedding plans. Daniel and a pregnant Chloe were married in the park on October 14, 2010. A few weeks later Chloe gave birth and Daniel was thrilled to spend time with his new son, Parker. But their happiness was short lived. On the day of Parker's baptism, Caroline Brady confessed that she had switched the paternity test results and Philip was really Parker's father. Devastated, Daniel divorced Chloe and tried to move on with his life.
Daniel met Jennifer while working at the hospital and the two began casually dating. Both knowing that they had come fresh of divorces, they wanted to take things slow. But Daniel soon found himself very happy with Jennifer and wanted to move things along. Jennifer returned his feelings and the two began happily dating.
One night while Jennifer and Daniel were away for the weekend at a spa, Melanie called Daniel and asked him for the code to the free clinic outside of town. Worried that she was in some kind of danger, Daniel and Jennifer rushed to the clinic. There, they found Melanie trying to save a badly beaten E.J. Daniel jumped in and started performing surgery to stop the internal bleeding. Jennifer went to get Carly to help with the surgery. Once E.J. was stable, Daniel took him to Salem U Hospital. To protect everyone involved (including Brady, who was the one who beat E.J.) Daniel told Lexie that he had found E.J. on the pier and, alone, performed all surgeries to stabilize E.J.
To make up for the spa weekend that they had to cut short, Daniel invited Jennifer to go to San Francisco with him. Jennifer abruptly said no and broke up with him. Daniel had no idea that Jennifer was intentionally pushing him away because Jennifer learned that Carly had feelings for Daniel and was taking pills. Jennifer thought that if she gave up Daniel, Carly would stop abusing the drugs. Eventually, Jennifer came clean with Daniel about Carly's feelings, but did not tell him about the pills. Daniel went to talk to Carly to tell her that there was no chance that the two of them would be anything more than friends.
When a picture of a passed-out Carly surrounded by pills showed up online, Daniel went to find her. Daniel found Jennifer at Carly's hotel room. Jennifer confessed that she had known about the pills all along. Daniel was furious with Jennifer for keeping Carly's addiction a secret. While Daniel and Jennifer were arguing, Carly slipped out the bathroom window. Daniel, Jennifer, and Melanie began looking for her.
Their search was not successful. However, Quinn Hudson found Carly in an alley and helped her realize that she needed to return to the people who loved her and enter rehab. Daniel was thrilled when Carly came home safe. Happy that his friend was on her way to being healthy again, Daniel turned his attention back towards Jennifer.
On the night of the Horton Square dedication, Daniel asked Jennifer to move in with him. Just as he got the question out, Jack, Jennifer's ex-husband fell from the above balcony onto the cake that Jennifer and Daniel were standing next to. Suddenly, Jennifer had a big decision to make - Jack or Daniel. Both men agreed to give her some time to make her decision and both spend alternating days with Jennifer while she made up her mind.
At the same time, another woman entered Daniel's life. Bo and Hope found documentation at Alice's house, leading to the revelation that Daniel's parents had used an egg donor to conceive Daniel. However, it turned out that the eggs were actually stolen, and the eggs we're Maggie's. Daniel tried to process the idea that Maggie was his biological mother, despite his parents never saying anything to him about it. Quickly, he began to accept the idea of Maggie as his biological mother.
With his recently renewed sense of family, Daniel realized that Jennifer needed to give her family with Jack a fair shot. So, he went to Jennifer and told her that he would back off while she gave Jack a chance.
Around the same time, Daniel received some medical test results back. Because he and Melanie were both related to Maggie, they were tested for MG. Neither had the gene, but Daniel was still experiencing unexplained tremors. Lexie finally diagnose with intention tremors, probably caused by a small stroke he suffered in his sleep. The tremors were incurable, which meant that for the time being, he could no longer be a surgeon. This news, coupled with the grief over losing Jennifer, prompted Daniel to leave Salem for a bit to clear his head.
When Daniel returned to Salem, he decided to focus on being a doctor and officially broke things off with Jennifer. He wasn't single for long, as he soon became wrapped up in Nicole's scheme to keep her baby from E.J. Daniel knew that Nicole switched the paternity tests, but kept quiet about it. Shortly after, Daniel and Nicole started sleeping together. They both insisted that they were just "having fun." But, Daniel seemed to be developing feelings for Nicole. That is, until Jack died and he Daniel realized that his feelings for Jennifer never went away.
Nicole was furious and began scheming to keep Daniel and Jennifer apart. Daniel was honest with Nicole that he did not return her exact feelings, but he did agree to go away to Hawaii with her to start a new life. However, Nicole tragically miscarried just before she was to give birth. After she left the hospital, Nicole went to Daniel's apartment and heard Jennifer leaving a voicemail for Daniel to meet her in the town square. Nicole went instead and confronted Jennifer. Jennifer tried to walk away, but Nicole rushed after her. Nicole followed Jennifer up the stairs and grabbed Jennifer's arm. When Jennifer jerked her arm away, Nicole fell down the stairs. When people rushed to see if Nicole was okay, Nicole immediately said that Jennifer pushed her.
Nicole was rushed to the hospital where she delivered her baby. When Dr. Davis pronounced that the baby was dead, Nicole insisted that Jennifer was the one who killed the baby. Jennifer was arrested. But, Daniel was sure that Jennifer was innocent. So, Daniel offered Nicole a deal -- drop the charges against Jennifer and he would still move to Hawaii with Nicole. Nicole agreed and told the police that she misremembered the events of her fall and that her fall was an accident.
As Daniel was closing up some loose ends at the hospital, he came across an infant t-shirt in the lost and found that he recognized as part of a set that Nicole had purchased for her baby. Wondering why it was in an exam room, Daniel looked into Nicole's last doctor's appointment and learned that Nicole had actually miscarried the baby before the altercation with Jennifer on the stairs. Daniel confronted Nicole with the information. Rafe, E.J., Jennifer, Brady, and Abigail all witnessed it. Nicole cried and admitted that she had, in fact, made the whole thing up to keep Daniel from going back to Jennifer. Daniel told Nicole that they were not moving to Hawaii.
But, Daniel did not hold a grudge against Nicole. Instead he just focused on moving on with Jennifer. However, Chloe soon returned to town with the news that Parker actually was Daniel's biological child. Daniel was thrilled, but he didn't count on Chloe wanting him back as well. Chloe schemed to break Jennifer and Daniel up, despite his protests that he does not want to be with Chloe.
Finally, Chloe went to Jennifer and told her to give up Daniel, or Daniel would never see his son again. Jennifer tried to break up with Daniel, but he was sure that someone was forcing her to do so.