The Sign of the Four by Arthur Conan Doyle

Two rings surrounding a person on a purple background.  Two open white pages on an orange background.  A black background with a white W.  A black background with a white symbol, that has a black play symbol in the middle.  A black background with a white tentacled cat.

Suggested Price: $1.99

The Sign of the Four by Sir Arthur Conan Doyle is the second novel to feature his most famous creation, Sherlock Holmes. Holmes & Watson are approached by Dr. Watson’s future wife, Mary Morstan. Mary has been getting an odd gift every year for the previous six years: a pearl. With the last pearl, she also receives a letter asking to meet someone in private. She takes the case to Holmes & Watson, who take on the case and kick start a new adventure for them.

Doyle appeared to be a workaholic when it came to Sherlock Holmes, writing four novels and 56 short stories (which have been collected in a further five anthologies). The 60 official stories represent the entirety of the official Sherlock Holmes canon, although there have been many unofficial works since. The works not written by Doyle are known as extracanonical works. The delineation is not always clear, with some contending that a few of the extracanonical works are as good as what Doyle had written, and ought to be a part of the main canon. While that is unlikely to happen, as Sherlock Holmes (the character) is in the public domain, the unofficial canon will only grow with time.

You can buy a copy of The Sign of the Four here and an illustrated version here.