Tusk, Part 1 (牙（タスク） その① Tasuku Sono 1), originally The President's Orders: 'Search for the Corpse', Part 1 (大統領命令「死体をさがせ」① Daitōryō Meirei 'Shitai o Sagase' 1) in the UJ release, is the twenty-fifth chapter of Steel Ball Run and the seven hundred seventy-seventh chapter of the JoJo's Bizarre Adventure manga.
A narration presents Joseph of Arimathea, the man who took the body of the deceased Jesus Christ, cleaned and buried him. Some time later, Joseph of Arimathea drew the map of an unknown continent marked at various locations. The map was kept in an English monastery until the 15th Century, when it was stolen and the American continent was discovered.
In the present, Gyro and Johnny are attacked by German competitor Fritz von Stroheim, who reveals himself as a cyborg. Fritz unhorses both riders and shoots at Gyro, but the Spin makes Gyro invulnerable to bullets as he spins the Steel Ball on his hands. Fritz orders Gyro to drop his balls or else he'll shoot Johnny and his horse. Gyro complies, only to reveal that the Spin shaped several spheres from the rock he was leaning against, which smash into Fritz's face, defeating him. Johnny tells Gyro that the attacks are too frequent and violent for Gyro's country to justify all of them, an explanation Gyro maintains nonetheless. Suddenly, Johnny sees a Left Arm emerging from his own, and reentering his body again. Johnny realizes that this Arm isn't simply a Stand.
In the train following the Steel Ball Run race, Steven inquires about Gyro, asking if, after crossing the Devil's Palm, Gyro was giving the impression of having found "something," especially a Corpse Part. When the assistant leaves, a man reveals himself from behind a curtain, saying that his agent Oyecomova failed to get a Corpse. Casually mentioning that killing Gyro could be troublesome if his Corpse Part vanished again, Steven becomes anxious, telling the man that it wasn't part of the deal. The man, showing Steven Joseph of Arimathea's map, tells Steven to ensure that the race goes on; Steven can only obey, as the man is the President of the United States. Lucy barges in the wagon with a coffee pot, which almost spills on the President when an agent stops Lucy. It disappears, only to fall from the ceiling, empty. Lucy notices from the train's shadow that someone is standing on the wagon's roof.
Johnny and Gyro are riding in the middle of the desert, discussing trivias. Suddenly Johnny realizes that Gyro has disappeared, and can't see him even if he is in the middle of a clear plain. Valkyrie and Gyro's packs disappear one by one, and finally, Johnny feels he being dragged upward by something. When he turns his head, whatever was dragging him disappears and Johnny remains on his horse, realizing that he is being attacked by a Stand User.