Sherlock Holmes (Christopher Plummer) is called to a meeting with the prime minister, Lord Salisbury (John Gielgud). the Home Secretary, Henry Matthews (Geoffrey Russell) and Sir Charles Warren (Anthony Quayle) [01:57:43]. The room is decorated to look like a masonic lodge. Note the tessellated checkerboard flooring and two pillars topped with globes.
Holmes accuses them of covering up the murders perpetrated by Sir Thomas Spivey (Roy Lansford), a physician and fellow freemason:
Holmes: "...who according to archaic ritual, butchered his victims." [02:05:28]
Holmes: ""I have evidence suppressed by you, Sir Charles; evidence which seem to accuse a member of the sacred order to which you all belong, You are all fremasons. You, Prime Minister, Home Secretary, Sir Charles, you and Spivey, all masons. And in discovering the involvement of a fellow mason you were sworn to protect him in his criminal intent."
Salisbury: "Sir Charles ' career is ruined."
Holmes: "What sort of ruin does he face? Will the masons punish or reward him? He kept faith with you. Your oath of fellowship binds you to support him."
Note that there is no documentation of a real Sir Thomas Spivey, and neither Salisbury nor Gull were freemasons.
Murder by Decree (1979)
Directed by Bob Clark, written by John Hopkins, Elwyn Jones. Christopher Plummer, James Mason, David Hemmings, Susan Clark, Anthony Quayle, John Gielgud, Frank Finlay, Donald Sutherland, Geneviève Bujold, Chris Wiggins, Tedde Moore, Peter Jonfield, Roy Lansford, Catherine Kessler, Ron Pember, Geoffrey Russell. 124 min, UK / Canada, English, Metrocolor, Mono.