Why Cameron Monaghan Is Leaving 'Shameless'

Shameless fans were devastated when they learned they'd be losing not just Emmy Rossum's Fiona Gallagher during season 9, but Cameron Monaghan's Ian Gallagher as well.

Monaghan revealed via a lengthy social media post on Monday that the upcoming episode of Shameless will be his last. Fans wondering why they'll no longer see Ian Gallagher on Showtime Sunday nights received a quasi-answer from the 25-year-old, but many questions remain.

In his Instagram post announcing his departure, Monaghan revealed that he's known he'd be leaving the series "since last year," but that he wanted to keep it a surprise from fans, as Ian's journey has been an unsure one.

"The next episode will be my last. I have known since last year, but I didn't want to give it away too early as I wanted this season to be a surprise for the audience, allowing them to experience Ian's unsure journey with his character," he wrote.

Whether or not the decision to leave was his own, his exit has been set up by his character's story arc over the past two seasons. Slowly gaining fame as "Gay Jesus," Ian, who has struggled with his bipolar diagnosis throughout the series, launched a sometimes violent campaign protecting at-risk youth from religious bigots. Season 9 opened with him in jail after he was arrested for blowing up a van in the season 8 finale. In the most recent episode, he pleaded not guilty to setting the van on fire by reason of insanity.

In a preview for Monaghan's final episode, Ian seems eager for a peaceful night at home before spending time in jail.

It's possible his exit is simply the result of his character's fate, or perhaps he's leaving the show to pursue other projects — or perhaps a combination of both.

Monaghan seemed eager to come to terms with his exit in his announcement, saying, "All good things come to an end. An old cliche, but one that rings true with a sincerity and clarity especially in moments like these. Everything ends."

After ten years on the show, Monaghan wrote that he "came of age in so many ways, both legally and personally" while working on Shameless. "I was very lucky to mature and grow with this show. Experiencing so many firsts, maturing as an actor, a professional, and a human. In the process gaining friends, family, and the best coworkers a very lucky actor could ask for, and for this I can be nothing but gracious."

He gave Shameless fans hope that there was room for an Ian Gallagher return, concluding his announcement with, "Goodbye, Ian Clayton Gallagher. We'll meet again?"

Earlier in the summer, Rossum announced her departure from the show, which came as a sudden shock to fans as she plays the matriarchal character Fiona, around whom many of the show's plot lines revolve. She also described an open-ended departure for her character.

"I know you will continue on without me, for now. There is much more Gallagher story to be told," Rossum wrote on Facebook. "I will always be rooting for my family. Try not to think of me as gone, just think of me as moving down the block."

Shameless airs at 9 p.m. ET on Showtime.