Shark Island is a prison located in the Gulf of Mexico, surrounded by the sea. Not only that, there are special parapet waters around the prison, which are full of sharks. It is almost impossible for prisoners locked up here to escape. But someone succeeded. In 1865, President Lincoln was assassinated by Booth at the Washington Theater. Booth broke his leg when he jumped from the box to the stage, and he and his companions fled in the rain all night. On the way, his legs couldn't hold on any longer, and they broke into the home of Samuel Mudd, a country doctor. Dr. Mudd treated Booth without knowing that President Lincoln had been assassinated. Booth quietly scratched the name off his boot and threw it aside. The next day, during a nationwide manhunt, the military found the boot at Mudd's home. Mudd was arrested by a military court on charges of conspiracy to assassinate. Mudd defended himself, saying he was innocent and insisting that the doctor's job was to treat anyone in need. Booth was killed in the manhunt, the other accomplices were hanged, and only Mudd survived and was sentenced to life in prison. Ma de was held in Shark Island prison, and the prison authorities hated him because he conspired to assassinate President Lincoln but was not hanged. The warden has been working with horses everywhere from the very beginning.