Hardy plays Harry Da Souza, the professional mediator of the fictional Irish Harrigan crime family. Brosnan plays Conrad Harrigan, the head of the Harrigan family, and Mirren is Maeve Harrigan, Conrad's wife and the matriarch of the Harrigan family.

Joanne Froggatt (pictured left), best known as Anna Bates from the long-running ITV/PBS drama Downton Abbey, joins the series alongside CSI: Vegas actress Mandeep Dhillon (pictured center) and Jasmine Jobson (pictured right, Top Boy (2019)).
Froggatt plays Jan Da Souza, Harry’s wife. Dhillon plays Seraphina, Conrad’s daughter. Jobson plays Zosia, who works for Harry and is one of his closest associates.
The synopsis describes the series as “an exciting new global crime drama centered on two warring London families whose businesses span the globe and the fiercely loyal ‘fixer’ who must protect one of them at all costs.”
Froggatt is a veteran of the small screen. From 2010 to 2015, she played Anna Bates in Julian Fellowes's hit series Downton Abbey, for which she received three Emmy nominations and won a Golden Globe for Best Supporting Actress. She will reprise the role in the third Downton Abbey spin-off film, currently scheduled for September 2025. Her other roles include the BAFTA-winning BBC drama Sherwood (2022) and ITV's Angela Black.
Dhillon is best known for her starring role in CBS’s CSI: Vegas. Her other television roles include the Netflix comedy series After Life, in which she co-stars with Ricky Gervais. She currently stars in the BBC One comedy series Avoidance.
Jobson is best known for her role as Jaq in the groundbreaking British crime series Top Boy (2019). She won a TV BAFTA earlier this year for her performance in the series’ final season. Her other television roles include the ITVX limited series Platform 7.