ITV will air the latest episode of Grantchester season four on Friday (February 8) at 9pm, with the cast investigating another murder. Jemma Redgrave and Nathaniel Parker are joining the Grantchester season four cast alongside series regulars like Georgie Keating (played by Robson Green), Will Davenport (Tom Brittney) and Cathy Keating (Kacey Ainsworth), whose plot in last week's episode left fans raging. James Norton left the Grantchester cast earlier this year to focus on other projects. Related articles Grantchester season 4: James Norton speaks out on why he quit role Grantchester season 4: Sidney's ‘gruesome’ exit revealed? Who is in the cast of Grantchester? DI Geordie Keating - Robson Green Geordie Keating is an old-fashioned policeman who, in Robson Green’s words, “blames Elvis Presley for broken Britain in the 1950s, corrupting the minds of everyone.” He is played by Robson Green of Soldier Soldier, Wire in the Blood and the band Robson and Jerome, which he sang in alongside Game of Thrones’ Jerome Flynn. Sidney Chambers - James Norton Sidney Chambers is what ITV calls a “charismatic, jazz-loving clergyman” who for the last three seasons has been solving crimes with Geordie. The character is portrayed by James Norton who, since appearing in Grantchester found fame in McMafia and has appeared in films like Hampstead and Flatliners. ITV has not yet revealed when Sidney will be leaving Grantchester, though according to the listings he will appear in at least the first two episodes. GRANTCHESTER SEASON 4 RELEASE DATE, CAST, TRAILER, PLOT The Grantchester season 4 cast is led by Tom Brittney, Robson Green and James Norton (Image: ITV) Will Davenport - Tom Brittney Will Davenport is the new clergyman crime-solving partner of Geordie, described by Tom Brittney as, “an affable, charming, friendly character who tries to bring his youthful energy to the church.” Brittney has previously appeared in Unreal, Outlander and The Five, as well as 2017 movie Film Stars Don’t Die in Liverpool. Mrs Chapman - Tessa Peake-Jones Mrs Chapman is Sidney’s intimidating mother, who last season married her second husband Jack Chapman (Nick Brimble). Tessa Peake-Jones, who plays her, is best known as Only Fools and Horses’ Raquel, though she has also appeared in The Demon Headmaster, Unforgotten and Holby City. WHO IS TOM BRITTNEY? Related articles Grantchester season 4 spoilers: Tom Brittney drops James Norton exit Grantchester season 4 location: Where is Grantchester filmed? Tessa Peake-Jones and Nick Brimble are in the Grantchester season 4 cast as the Chapmans (Image: ITV) Cathy Keating - Kacey Ainsworth Geordie’s wife is Cathy, who in Grantchester season four is starting to gain independence after getting a job in a department store. Cathy is brought to life by Kacey Ainsworth, who found fame as EastEnders’ Little Mo, but also had lead roles in Holby City spin-off Holby Blue, The Worst Witch and The Wright Way. Leonard Finch - Al Weaver Another member of the Grantchester clergy is Leonard Finch, the junior Anglican curate. He is played by Al Weaver, who appeared last year in Press and Peterloo and has previously had roles in Doom, Southcliffe and the 2010 version of The Nativity. HOW MANY EPISODES IN GRANTCHESTER SEASON 4? Grantchester season 4's cast also includes Kacey Ainsworth (centre) (Image: ITV) Jack Chapman - Nick Brimble Jack Chapman is Mrs Chapman’s new husband, a wealthy man intent on spoiling his wife. The character is portrayed by Nick Brimble of Emmerdale, Robin Hood: Prince of Thieves and 1980s drama William Tell. The Grantchester season four cast of characters also includes Daniel Marlowe (Oliver Dimsdale), Violet Todd (Simon Brown) and Reverend Nathaniel Todd (Paterson Joseph). Grantchester season 4 airs Fridays at 9pm on ITVAll rights reserved for this news site express.co.uk and under his responsibility