"How often have I said to you that when you have eliminated the impossible, whatever remains, however improbable, must be the truth?" - Arthur Conan Doyle Miss Mary Morstan arrives at 221B, Baker Street to seek help for finding her missing father. He had been an officer in the British Army and disappeared without a trace when he arrived in London. But that's not all! She also receives anonymous gifts of pearls and a letter requesting her to meet an unknown person. Who is sending her these pearls? Will Sherlock be able to bring her missing father back? The Sign of the Four takes Sherlock and Dr Watson on a rollercoaster ride where they reveal the mystery of a hidden treasure to track down the criminals.