ITV has released details of Nemesis and Towards Zero, the last instalments filmed with McEwan before her retirement.
Nemesis, which will air in August, sees Miss Marple sent on a coach tour in a message from a recently deceased man named Mr Rafiel. Stars will include Grant, Johnny Briggs, Burton and Will Mellor.
Towards Zero, in which Marple investigates a murder at a sexually-charged party held by an aristocrat, features Dame Eileen Atkins, Tom Baker, Julie Graham and Paul Nicholls.
Julia McKenzie will take up the role of Miss Marple in a new series next year.