Theory:

     Dr. Watson visits the apartment of his friend Sherlock Holmes. He finds detective Holmes talking to a client with bright red hair, Mr. Jabez Wilson. Holmes asks Dr. Watson to hear the unusual story of the client.

     Wilson says that he runs a pawnshop. One day in his shop, his assistant, Vincent Spaulding, showed an advertisement in the newspaper that announced an opening in the Red-Headed League. The announcement promised a salary of four pounds a week. Spaulding urged Wilson to apply. The timid red - haired pawnbroker did so. Wilson was accepted into the League by Mr. Duncan Ross, the head of the League.
 
     He learned that the nominal duties consisted only of his coming to the office from \(10:00\) a.m. until \(2:00\) p.m. each day and copying out the Encyclopaedia Britannica in longhand. This he did for eight weeks until one day he arrived at the office to find it closed, with a notice on the door that the Red-Headed League had been dissolved. He was so disturbed by the thought that someone had been playing a practical joke on him that he came to Holmes for a solution. Holmes promises to look into the case and Wilson leaves. Holmes and Dr. Watson move to Wilson’s shop in Saxe-Coburg Square at once.

Let’s read this play extract to know the happenings.

     (Outside Wilson’s shop in Saxe-Coburg Square. Holmes is walking up and down. Now and then he hits the ground outside the shop with his walking stick. Then he knocks on the door of the shop. Spaulding opens the shop door. The legs of his trousers are dirty.)
Explanation:
 
Dr. Watson goes to the home of his detective friend Sherlock Holmes where he saw him talking to the person who has a bright red hair named Jabez Wilson. Holmes invites Dr. Watson and wants him to hear the story of his client Mr. Wilson as he never heard of such a case before.
 
Mr. Wilson said he was a small businessman and run a pawnshop. He has one assistant named Vincent Spaulding. One day Vincent Spaulding drew the attention of Wilson by showing him an advertisement in the newspaper stating that there is an opening in the Red-Headed League in which all red-headed men are eligible to apply. The advertisement also stated that they are going to pay a salary of four pounds a week. Spaulding encouraged Wilson to apply for the job as he is red-headed. The fearful pawnbroker applied for the job to earn some money as he was not earning enough from the shop. Mr. Duncan Ross was the head of the league and selected Wilson into the league.
 
redhead.png
Red- Headed man.

Wilson's only duty was to go to the office for \(4\) hours from \(10.00\) A.M till \(2:00\) P.M. every day and copy the Encyclopedia Britannica in longhand. After eight weeks of working for the league one day when he arrived at the office, he saw a notice on the door which say's that the Red-Headed League was closed. Wilson was not happy by seeing the notice and got suspicious about the Red-Headed League as they are playing some practical joke on him. This leads Wilson to come to Holmes to understand the reason behind why the league was closed. Holmes agreed to take up the case and promised Wilson that he would find the mystery behind it.
 
Holmes and his friend Watson went to Saxe-Coburg Square where Wilson had his pawnshop. Holmes was walking here and there outside Wilson's shop by tapping the ground with his walking stick. After watching outside the shop, Holmes knocked on the door of the pawnshop, and Spaudings opens the door. Holmes notices that the pants worn by Vincent Spaulding were dirty.
 
Meanings of difficult words:
 
Numbers
Word
Meanings
1.
Detective Investigator.
2.
Client Customer.
3.
League Association.
4.
Pawnbroker A person who lends money at interest on the security of an article pawned.
Reference:
State Council of Educational Research and Training (2019). Term-1 English Standard-7. The Red-Headed League by Sir Arthur Conan Doyle (pp. 45-49). Published by the Tamil Nadu Textbook and Educational Services Corporation.