The character will make her final appearance in this year's Christmas special.
News broke at this weekend's San Diego Comic Con that while Pearl Mackie would be reprising her role as Bill Potts in the upcoming 'Doctor Who' Christmas special episode later this year, it would be the last time she'd step into the companion's shoes for the foreseeable future, as she won't be making a comeback in the new series next year.
Peter Capaldi and Pearl Mackie as The Doctor and companion Bill Potts
The announcement will come as a blow to many fans of the sci-fi series, who have really warmed up to the companion Bill ever since her debut earlier this year, following the departure of another fan-favourite, Clara (Jenna Coleman). Bill had come onto the show at the time because of, as well as her talents, the need to bring more diversity to the series.
Though she's on her way out, that doesn't mean this diversity is set to end. New showrunner Chris Chibnall - who'll be replacing Steven Moffat on the new series - has signed up 'Broadchurch' favourite Jodie Whittaker to become the first female on screen incarnation of The Doctor, splitting the viewers on whether it was the right decision or not.
None of that matters however as it is indeed Whittaker who'll bring Doctor 13 to life. News on exactly who'll be playing her companion however is yet to break. Traditionally, companions have been female - later male or female - so there's definitely going to be some big options for Chibnall and the team behind-the-scenes on 'Doctor Who' to consider.
Rumours suggest that former Doctor 13 frontrunner Kris Marshall could be the man stepping into the companion role, but again, nothing official has been said.
Though she's out of the show after Christmas, Mackie did tell her fans to "never say never" about a potential return at some point down the road. For now though, we've got her final scenes set to air later this year, when she and Capaldi's Doctor will be able to say a proper goodbye not only to each other, but to the millions of people watching at home.
'Doctor Who' returns to BBC One at Christmas before going on a break before its 11th series in 2018.