First broadcast 9th May 2010.
An Oxford professor, also an amateur astronomer and recently renewed churchgoer, is found dead in the school observatory under suspicious circumstances.
Warren Clarke - Roger Temple
Deborah Cornelius - Dr Ella Ransome
Christopher Bowen - Professor Andrew Crompton
Sophie Ward - Isobel Crompton
Clare Holman - Dr. Laura Hobson
Robert Hardy - Sir Arnold Raeburn
Ruby Thomas - Kate Cameron
Diana Quick - Gwen Raeburn
Anthony Calf - Malcolm Finniston
Jonathan Cullen - Father Francis
Annabelle Apsion - Babs Temple
Andrew Hawley - Jez Haydock (as Andrew Hawyley)
Kevin Whately - DI Robert Lewis
Laurence Fox - DS James Hathaway
Bernard Lloyd - Ted Temple
Liz Crowther - Mrs Leeming
Ben Addis - Junior Porter
Nicholas Howe - Undergraduate
Rebecca Front - Chief Superintendent Jean Innocent
Robin Kermode - Interviewer
Colin Dexter - Diner
Chris Wilson - Police Firearms Tech
