The Sign of Four (1987)

Mary Morston (Jenny Seagrove) arrives at Baker Street to consult Sherlock Holmes (Jeremy Brett).  Watson (Edward Hardwicke) is immediately drawn to her beauty.  She explains how her mother died when she was an infant and her father, who was posted in India, sent her to live in England.  When she was 17, her father was to visit.  She went to his hotel, and he was absent.  She did recover a peculiar map that bore a mark, 4 in Sanskrit.  "The Sign of Four," Holmes remarked.  That was 10 years ago, and she has no idea what happened.  However, six years ago, she received a pearl.  There was a note enclosed that said she had been wronged and the pearl was payment.  Each year since then, another pearl has arrived.  Holmes grew impatient with her tale.  That morning, she had received a summons and was allowed to bring two companions, provided they were not police.

The trio arrived at the home of Thaddeus Sholto (Ronald Lacey), son of Major Sholto.  Coincidentally, Sholto was a former comrade of Mary's father in India.  Thaddeus explains that Mary's father had confronted his father about a treasure, died of a heart attack during the argument.  His father died six years ago, failing to reveal the location of the mysterious treasure to his sons though he did have a necklace adorned with pearls, the very pearls that Mary had been receiving.  His brother has finally located the treasure and Thaddeus is determined to share with Mary.

The four depart to meet with Bartholomew Sholto but find him dead in a room locked from the inside.  The treasure is gone.  The police immediately arrest Thaddeus.  Can Holmes unravel the clues and locate the murderers?  Obviously.  Like The Crooked Man, this mystery tracks back to events during the Indian Mutiny (1857).  It is just a matter of Holmes laying hands on the criminal and then having him explain the backstory.

Very entertaining.  Holmes makes use of the Baker Street Irregulars, which is both funny and brilliant.  His band of street urchins comb the city to make a search that he could not hope to perform.  Holmes also demonstrated his talent for disguise.  The one failing is that young actors should have portrayed some of the characters during the mutiny; the same man playing both 20 and 50 just didn't work.

Highly recommended.