Chapter 20

The Tragedy at Sea (Jack the Ripper and Zeppeli the Eccentric - Part 3 in the JoJonium release) is the twentieth chapter of the JoJo's Bizarre Adventure manga. It is also the twentieth chapter of Part I: Phantom Blood.

Summary
It has been a week since Jonathan first began his training with Zeppeli in the art of the Hamon energy. Currently, Jonathan is attempting to figure out 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 longer at the wrist when he punches. Zeppeli tells Jonathan then that he will not be able to fight the Stone Mask with power and speed alone, and also that the Hamon 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.

Will 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, and 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 withers 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 explained how the power of the Stone Mask and Hamon are one in the same and afterward Jonathan agreed to let Zeppeli teach him.

One week later, after night has fallen, Jonathan is meditating when Wang Chan confronts him. Wang Chan proclaims that he was sent by Dio to kill Jonathan, because Dio believes 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, and using the Hamon energy to soften the pain. Using this new-found knowledge Jonathan uppercuts Wang Chan with the hamon 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 hamon, but tells him that he still has much to learn.