We finally know why Tracy Spiridakos decided to leave Chicago P.D.

The announcement was made ahead of Season 11 that it would be her final season playing Detective Hailey Upton. But she never went public with the information.

Instead, Tracy let the season play out, and ahead of the season finale, she has finally addressed her departure.

Tracy joined the show at the end of Season 4, becoming an important part of the Intelligence team and vital to the show following the exit of Sophia Bush (she played Detective Erin Lindsay).

Her character had many fans, especially when Upton’s relationship with Detective Jay Halstead (Jesse Lee Soffer) moved forward.

Many Chicago P.D. fans still share the hashtag UpsteadForever when posting about the couple and the show on social media.

Tracy Spiridakos explains her Chicago P.D. exit

“I decided at the end of my sixth season, which is when I had reached out to Gwen [Sigan] and to everyone at Wolf [Entertainment] to let them know that I just wanted to do one more year. I wanted us to send out the character with one last season,” Tracy Spiridakos told Variety.

She referred to Chicago P.D. Season 5 as her first full season after appearing in only three episodes at the close of Season 4. It means she decided to leave at the end of Season 10 (last spring).

“It was a hard decision — very, very hard. I love everybody on the show — cast, crew, producers, writers, everybody. It’s such an incredible team. I was just curious what was out there for me and wanted to switch it up, and that was it,” Tracy added.

The final episode for Tracy arrives at 10/9c on Wednesday, May 22. After it debuts on NBC, the episode will be available for streaming on Peacock.

Tracy also provided a fun tease about her final episode – an episode some Chicago P.D. fans worry Hank Voight will die in.

“I don’t think anyone sits down the whole episode… There’s a lot of really vulnerable moments. We see these characters, who we haven’t necessarily seen be so vulnerable, you see a lot of that come through as well,” Tracy teased about the season finale and her last Chicago P.D. episode.

A dramatic night for One Chicago

Chicago P.D. fans do not want to miss the final episode for Tracy Spiridakos.

The Chicago Fire finale has its emotional goodbye an hour earlier that night.

Saying goodbye to popular characters is not a new endeavor for One Chicago, but this could be a difficult night for long-time viewers.

Previous episodes of all three Chicago-based shows are available for streaming on Peacock.

Chicago P.D. airs Wednesday at 10/9c on NBC.