The "object of value" in this Upstairs, Downstairs episode is a diamond brooch owned by the widowed mother (Cathleen Nesbitt) of Lady Marjorie Bellamy (Rachel Gurney). When the brooch disappears, everyone -- both "upstairs" and "downstairs" -- falls under suspicion. Things reach the point where it seems that the long-standing atmosphere of mutual trust and respect at Eaton Place may be permanently shattered. Written by Jeremy Paul, "Object of Value" first aired in England on December 15, 1972, and in the United States on March 3, 1974. ~ Hal Erickson, All Movie Guide