Secrets are not set to be forever while "Private Practice" actress Kate Walsh negated rumors that she would be going to return in the second half of "Grey's Anatomy" season 12.

Rumors on Nathan's (Martin Henderson) true identity in "Grey's Anatomy" season 12 continues to ignite, according to Christian Today. According to speculations, Nathan was in fact a transgender and he was Owen's (Kevin McKidd) sister, which opposes other rumors saying that the character was Owen's brother-in-law.

It can be recalled that Nathan had a one on one conversation with Dr. Meredith in the last mid-season finale of "Grey's Anatomy." It is noted in the episode that Owen's sister was mentioned and it is speculated that she died, leaving Owen with no choice but to set Nathan accountable to the incident.

Another slice of the storyline that proves Nathan's identity is the when Owen's mother visited the former in Grey Sloan Memorial Hospital. Owen's mother saw Nathan and hugged him, with the latter calling the woman his "mother." This indicates the potential familial link between Owen and Nathan, with the latter as Owen's sister who had undergone surgery.

In other news, Walsh, who plays Addison Montgomery in "Grey's Anatomy" debunked the rumors saying that she would come back to the second half of the medical drama series. In her previous interview with Hollywood Life, Walsh said that she had done the role for nine years and it was important for her to move on as an actress.

For Walsh, she affirmed that the rumors are "hoax" and she was happy, grateful, and thrilled that she had gotten to do the role. In the same interview, the actress said the fate of her character is on the hands of the show's writers and executive producers. She added that Montgomery could have been on her third husband or with Jake, with three more kids.

"Grey's Anatomy" season 12 is set to return on Feb. 11 on ABC.