Suranne Jones shared the first photo of the Doctor Foster cast reuniting ahead of the long-awaited third series.
The BBC psychological thriller series debuted in 2015, with a second series following two years later.
It was created and written by Mike Bartlett, taking inspiration from the Greek myth of Medea.
Coronation Street alum Suranne, 47, plays Gemma Foster, who at the beginning of the series suspected husband Simon (Bertie Carvel) of having an affair.
Taking to Instagram, the actress shared a snap of herself, Bertie and their on-screen son Tom Taylor ahead of the show's return.
She captioned: 'Just your average family trying to work through some st.... Nothing to see here!'
The BBC previously confirmed that filming will begin for season three in Spring 2026.
Talking about reprising her role as Gemma, actress Suranne said: 'When I got the call to ask if I wanted to return as Gemma Foster, I knew the time was right.
'We needed space from the first two series, and we needed Tom - Gemma and Simon's runaway son - to return as an adult with questions.
'For me, this time around it's about accountability and questioning - 'can we ever truly sever ties with our past and the damage or traumas that haunt us, so we can fully move forward?' Gemma and Simon have so much to unpick!
'It's been an exciting time working with the brilliant Mike Bartlett again, and the team at Drama Republic, on the scripts and now I can't wait to start filming.'
Meanwhile executive producer Mike Barlett added: 'I've always hoped that we'd get to tell the final part of Gemma's story - which is about a woman seeking justice in an unfair world.
'That feels as relevant now as when Gemma first found a blonde hair on the scarf.
'It's been a joy to team up once again with the hugely talented Drama Republic, the now very grown-up and brilliant Tom Taylor, the inimitable Bertie Carvel and of course, the incomparable Suranne Jones, to tell the final chapter of this story and revisit Parminster - where it turns out there's still secrets, betrayals, vengeance and perhaps one last dinner party...'
Director of BBC Drama, Lindsay Salt said of the return: 'It's a privilege to welcome Doctor Foster back to the BBC after almost a decade away.
'The extent to which the first two series gripped the nation is a credit to Mike's writing, the talented team at Drama Republic and our magnificent cast - and now we're ready do it one more time in this epic final chapter.
'Bring it on!'
The third season will be made by television company Drama Republic.
The executive producers for the company Rosanna Benn and Jude Liknaitzky said: 'We are so excited to be bringing the finale of Doctor Foster to the screen.
'Mike Bartlett has written thrilling, gripping, audacious scripts that see Gemma and Simon re-encounter one another ten years on and it is electrifying!!!
'We cannot wait to watch the phenomenal Suranne and Bertie together on screen once again.
'And to meet the grown-up Tom. It is honestly going to be an amazing ride!'