A steam launch the thieves use to escape

When did the Four take the treasure?

During the Indian Rebellion of 1857

The Sign of Four · GCSE English Literature revision

Mary Morstan asks Sherlock Holmes for help. Her father, Captain Morstan, vanished in 1878, and for six years she has been sent a pearl each year by an unknown person.
She meets Thaddeus Sholto, whose father, Major Sholto, had hidden a treasure from Agra in India. Thaddeus's brother Bartholomew finds it, but is murdered with a poisoned dart and the treasure is stolen.
Holmes and Watson track the thieves, with the dog Toby, to a steam launch, the Aurora, and chase it down the Thames. Tonga is shot and Jonathan Small, a one-legged man, is caught; but the treasure box is empty.
Small tells how, during the Indian Rebellion of 1857, he and three Sikh men (the Four) took the treasure, and how Sholto and Morstan betrayed them. Watson and Mary become engaged.

Greed and treasure, justice, the British Empire, friendship, and reason and detection.
Published in 1890. It reflects Victorian London and the empire in India; its descriptions of Tonga show the racist attitudes of the time.

A detective novel narrated by Dr Watson, with Holmes's deductions, a chase and a confession that explains the past.

Who brings the case to Holmes?: Mary Morstan: Her father vanished in 1878.
What has Mary received each year?: A pearl: They come from part of the Agra treasure.
How is Bartholomew Sholto killed?: With a poisoned dart: Tonga fired it.
Who narrates The Sign of Four?: Dr Watson: He becomes engaged to Mary.
What is the Aurora?: A steam launch the thieves use to escape: Holmes chases it down the Thames.
What happened to the treasure in the end?: Small threw it into the Thames: The box is empty.
When did the Four take the treasure?: During the Indian Rebellion of 1857: Small explains the story in his confession.
Which theme is shown by Major Sholto's betrayal?: Greed: The treasure brings suffering to everyone.