The Sign Of The Four Book Review

The Sign Of The Four: Book Review by Dinh.

4.5 stars


The Sign of the Four Book Review


Mary Morstan’s father mysteriously disappears and a few years later there is an advert asking for Ms. Morstan’s address. Ms. Morstan decides to reveal her address and is then sent a valuable pearl.

Ms. Morstan consults Sherlock with these facts and he and Watson set to solve this case. Who sent her the pearl and why? What happened to Ms. Morstan’s father?

In this short book, Sherlock Holmes solves the case involving the lost treasure of Agra, India, and a pact made by four convicts.

Also, we see how Watson meets his future wife.



I just loved that this book starts off with a shocker- I was floored that Sherlock Holmes took drugs! I never knew that he did that.

He either injects cocaine or morphine.

To be precise, he injects the drug 3 times a day when he is not working on a case.  Sherlock injects a  7% solution of cocaine to stop him from being bored when he is  not on a case.

I guess  I shouldn’t be that surprised as today’s detectives sometimes take drugs to be “up” so they can catch the bad guy. I remember reading the Prey series and Lucas Davenport also takes drugs to help him.

The Sign of The Four




Here’s what I liked about the book:


Page- Turner

I enjoyed The Sign of the Four because it was a quick, easy read, with a good story line.

I liked that this case was a bit harder and that Holmes was stumped for a bit.

Sherlock did not have much information at first- only the facts that Ms. Morstan presented him.

It makes the story more enjoyable when Holmes had to work out the problem. It makes him more believable and not infallible when not everything is solvable right away.



This book also had a bit of romance, albeit it was only a bit and when I say romance it’s not romantic. What I refer to is Dr. Watson falling in love.

We see how Watson falls in love and meets his wife to be. Courtship back then was so different and it’s a nice compare the way things were done then.


Awesome Characters

I also liked that the Baker Street Irregulars were in this. How inventive of Holmes to have street urchins to do his legwork for him.

Both parties benefit. The street urchin boys get paid for their work and Holmes gets a wide network of spies around London to help him with his investigation.


Great Writing

Another thing that I liked about this book is that Conan Doyle writes in a clear, crisp manner. The focus is on the case and how it’s solved so there’s no excessive written descriptions of events that are not applicable.

Having said that, the only negative thing about this book is that it was short. Like the first book, it read like a short story and was done before I knew it.

So if you want a quick read, on a solvable mystery/detective case then this may be for you!

Get a copy of The Sign of the Four here. Or listen to it for free with an Amazon Audible trial.

Check out A Study in Scarlet or other book reviews.

22 thoughts on “The Sign Of The Four Book Review

  1. I actually have the entire Sherlock collection so it is more so a matter of me bothering to get around to it! And I’m looking forward to when I can finally do that. I love the fan base around Sherlock and have seen the movies and television show, as well as read many retellings. I did know he took drugs but I didn’t know that many detectives actually do that as well!

    1. Hi Olivia,
      thanks for sharing your thoughts.
      I know how it is with having a big TBR list. I hope you enjoy reading the Sherlock collection when you get a chance 🙂

      I am not sure how many detective books have detectives using drugs but I think that these days when we watch or read something it comes up as them using something to aid them in their crusade to fight or find the bad guy.

      Thanks for stopping by!

  2. Is drug usage more acceptable during this period in history? I’m not a smoker, but I do remember a couple of decades ago when smoking was considered hip. Though, it may not quite be an apple-to-apple comparison, but I wonderful if it was considered “okay.” =) Glad you enjoyed this one, Dinh. It’s a very thoughtful review!

    1. Hi Lonna!
      I think that people were not as aware of the effects of drugs back then. Holmes and Watson do know the effects but for Holmes I think the immediate gratification was more important than the long term side effects. Dr. Watson knew too well of the long term side effects and tried to talk to his friend Holmes but without success.

      I am not sure what the levels social acceptance of the drugs were back then. I don’t think that it was readily available for it to be an issue or concern.

      Thanks for stopping by!

    1. Hi Josephine!
      The book is a page turner and a great read. I love Sherlock Holmes stories whether it is a show, movie or a paper or audio book!

      If you enjoy the shows or movie then you would probably love the books.

      Thanks for stopping by! 🙂

  3. What an interesting sounding novel. I definitely have to check it out and you did a great job with the synopsis of everything. This definitely sounds like my kind of book. Thanks for sharing!

    1. Hi Howie,
      thanks for sharing your thoughts.

      I like Conan Doyle’s books. They are easy to read, page turners and the story line is great. I also like that we get the motive and the backstory to the crime. It helps to confirm Holmes’ theory and fills in the missing gaps that are unknown to Holmes and the reader.
      Thanks for stopping by! 🙂

  4. Sherlock Holmes has ADHD I think! He can be so focused on a case that he just forgets everything else and then he needs cocaine to keep his active mind from slowing down.

    Will add this to my TBR list.

    1. Hi Peter!
      I wouldn’t be surprised to find out that Sherlock Holmes has ADHD. Lots of real famous people have it.
      Holmes does show signs of being super focused when he’s on a case.
      Glad to hear that you are adding this to your TBR pile. 🙂

      Thanks for stopping in!

  5. An interesting review of this book. I am a great fan of Sir Arthur Conan Doyle and his Sherlock Holmes novels. Very surprised to learn about his drug taking as I always thought he got his ‘highs’ from puffing on his pipe. Maybe it wasn’t tobacco in the pipe!

    1. Hi Jim,
      thanks for sharing your thoughts.

      I associate Sherlock Holmes with a pipe as well and not him taking drugs! It was a big shocker for me.

      Thanks for popping by!

  6. What a great post and review. I always find it hard to get a gift for my brother for his birthdays. However, it is coming up in 2 weeks and I think I know what I’m getting him thanks to this post (he’s an avid reader). I’m sure he’ll enjoy this awesome book you mentioned.

    So thanks for this article.

    1. Hi Brandon!
      Thanks for your comments.

      It’s always nice to get books as gifts! I hope your brother enjoy this classic by Conan Doyle.

      Thanks for stopping by!

  7. Hi Dinh, sounds like a great read and you know I trust your recommendations! I do love a good mystery, but I’m so busy these days I’m too distracted to sit down with a nice fat book the way I used to. Something with some intrigue that’s a quick read sounds like just what I’m looking for.

    1. Hi Hindy!
      Thanks for the compliment 🙂

      I really enjoy reading Sir Arthur Conan Doyle’s works. So far his novels are short and sweet.
      I have book 3 – The Adventures of Sherlock Holmes in my to be read pile.

      Thanks for stopping by!

  8. Wow, what an insight into Sherlock Holmes, I love watching the old films when they come on TV but they certainly did not show him injecting drugs. Based on your overall review, I am certainly intrigued, this will be the next book I will be picking up.
    Thanks for the post, keep them coming.

    1. Hi Barry,
      thanks for your comments.

      I was so surprised by Sherlock Holmes injection cocaine or morphine. I had mentioned it to a friend and apparently the fact is well known. I guess I am not in the same circles.

      I just love finding out new things about icon characters I didn’t know before!

      Thanks for stopping by!

  9. I didn’t know that Sherlock Holmes was taken drugs either. That’s completely new to me. When I read a book and it excites me from the beginning to the end I tend to be a bit frustrated when it’s short.

    Thanks for sharing this post about Sherlock Holmes.


    1. Hi ToveL,
      Thanks for sharing your thoughts.

      I was very surprised to find that Sherlock Holmes took cocaine or morphine. I guess back then it wasn’t as widely known that the drugs are addictive and not good for your body. It certainly puts an interesting slant on Holmes and how he deals with boredom.

      I don’t like it when I am enjoying a book and then it ends but I guess it has to stop somewhere.

      Thanks for stopping by at Arlene’s Book Club!

  10. Another great review, Dinh!! I am adding this book to my wish list!! I have shared your site with a friend of mine that loves these types of books. Thanks again!

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