Frankie Drake Mysteries is heading to London for its third season, with Honeysuckle Weeks guest starring as Agatha Christie. The Foyle’s War actress appears in the season opener, which was filmed on location in England.

The Canadian period drama follows Frankie Drake, the first female private detective in 1920s Toronto, played by Lauren Lee Smith. In the London-set premiere, one of Frankie’s old wartime friends goes missing, and she joins forces with a young Agatha Christie to track her down before turning her attention back to cases at home.

Smith leads a cast that includes Chantel Riley as Frankie’s partner Trudy Clarke, Rebecca Liddiard as police morality officer Mary Shaw and Sharron Matthews as morgue attendant Flo Chakowitz. Wendy Crewson also returns as Frankie’s mother Nora.

Made by Shaftesbury for CBC and UKTV’s Alibi, the third season runs to ten episodes. After the London shoot, production moves to Ontario, with the new run set to take in British aristocrats, illegal boxing and a family secret from Frankie’s own past.