An emergency summons gathers Class S heroes at headquarters...and Saitama tags along. There, they learn that the great seer Shibabawa left the following prophecy: “The Earth is in danger!” What in the world is going to happen?! -- VIZ Media

A Study in Scarlet is the novel which first introduced Arthur Conan Doyle's iconic characters Sherlock Holmes and Dr. Watson. Published in 1887, it was featured in Beeton's Christmas Annual and marked the beginning of the world's fascination with this enigmatic detective and his partner.

The story is told from the perspective of Dr. John Watson, who, upon returning to London after serving in Afghanistan, finds himself in need of affordable accommodation. It is then that he meets Sherlock Holmes and the two decide to share a flat. Watson is intrigued by Holmes' eccentric behavior and vast knowledge in specific areas, yet his ignorance in others. Soon, Watson learns of Holmes' profession as the first "consulting detective" and quickly becomes involved in a case with him.

The mystery starts with the discovery of a man's body in an abandoned house, bearing no signs of injury but with the word RACHE written in blood on the wall. As they delve into the investigation, they uncover a series of unexpected twists and turns.