When paramedic Brian “Otis” Zvonecek died in a blaze of heroism, fans were heartbroken. But his departure was planned. Not so for another beloved Chicago Fire character who vanished mid-season… without explanation.
Actor Charlie Barnett, who played Peter Mills for the show’s first three seasons, disappeared so suddenly that even castmates were shocked. “One day he was there,” said a camera operator. “The next, his trailer was gone.”
Officially, the character left to run a family restaurant out of town. But behind the scenes, something deeper had happened.
Sources now reveal Barnett had become frustrated with the direction of his character. “He was being sidelined,” said a former script coordinator. “He started as a lead, then kept getting pushed out of major storylines.”
Barnett reportedly requested more meaningful arcs — particularly around Mills’ biracial identity and his struggle as a rookie. “He wanted complexity,” the source said. “What he got was silence.”
When he pushed harder, things soured. A tense meeting with producers led to a mutual decision: Mills would leave, no farewell tour, no dramatic send-off.
Even worse? A planned flashback sequence in Season 4, which would have featured Mills returning in a dream, was scrapped last-minute.
“He was erased,” said a former castmate.
Barnett has since spoken fondly of his time on the show — but fans still wonder what could have been.
And in a franchise built on loyalty, his disappearance remains one of Chicago Fire’s most unsettling mysteries
