Jack the Ripper and Zeppeli the Strange (3) (切り裂きジャックと奇人ツェペリ その③,Kirisaki Jakku to Kijin Tseperi Sono 3), originally The Tragedy at Sea (洋上の惨劇,Yōjō no Sangeki) in the WSJ release, is the twentieth chapter of the JoJo's Bizarre Adventure manga. It is also the twentieth chapter of Phantom Blood.
It has been a week since Jonathan first began his training with Zeppeli in the art of the Ripple. Currently, Jonathan is attempting to solve a problem he has during his sparring matches with Zeppeli. He knows that his arm is ten centimeters longer than Zeppeli’s; however, when they strike each other simultaneously, with matching speed and timing, Zeppeli somehow manages to hit first. Somehow, it appears that Zeppeli's arm extends at the wrist when he punches. Zeppeli tells Jonathan that he will not be able to fight the Stone Mask with power and speed alone, and also that the Ripple energy is sensitive to mental distress and grows stronger by the carefully maintained breathing rhythm of the user. Jonathan then reflects on the time when Zeppeli told him of his past, and why he seeks to destroy the Stone Mask.
William Anthonio Zeppeli was born to a family of scholars, and his hunger for knowledge of the unknown led him to join an archaeological team at his father's university. He traveled with them across the world. On a fateful voyage to an Aztec ruin, Zeppeli accidentally discovered the Stone Mask. On the voyage back, someone discovered the hidden power of the mask and slaughtered the crew one by one. Zeppeli tried to escape the massacre by jumping into the ocean, but the assailant caught up with him. As his blood was about to be drained, dawn broke, and the vampire disintegrated in the sunlight. As he withered away, Zeppeli discovered that the vampire was his own father, the leader of the archaeology team.
Zeppeli drifted for days at sea until a fishing boat rescued him. He was still concerned about the whereabouts of the abandoned ship and the Stone Mask, and feared that someone would discover the secret of the mask again. Zeppeli then explains how the power of the Stone Mask and Ripple are one in the same, and, afterward, Jonathan agrees to let Zeppeli teach him.
One week later, after night has fallen, Jonathan is meditating. Suddenly, Wang Chan confronts him. Wang Chan proclaims that he was sent by Dio to kill Jonathan, because Dio believes that he is the only one who knows of the secrets of the Mask that he wishes to keep hidden. As Wang Chan attacks, Jonathan goes to punch him, and, as he executes the punch, he realizes he can dislocate his joints by stretching his arm, using the Ripple energy to soften the pain. Using this new-found knowledge, Jonathan uppercuts Wang Chan with the Ripple energy, leaving a burn on his cheek. The zombie is shocked by the technique and retreats. Afterwards, Zeppeli congratulates Jonathan on defeating Wang Chan using Ripple, but tells him that he still has much to learn.