Dr. Stone › Saison 1 Dr. Stone : Stone World

Chapter 13 — Episode 13

**Beginning:** The episode opens with Chrome returning with sulfuric acid, the last difficult material needed. Senku announces that all necessary ingredients are now gathered and launches into an intense chemical cooking session. Step by step, he produces hydrochloric acid by mixing sulfuric acid with salt and capturing the gas, then creates chlorosulfuric acid using hot spring sulfur deposits, and obtains sodium hydroxide by electrolyzing saltwater — warning the group about the dangers of each substance along the way. **Middle:** Senku reveals that only three compounds remain — acetic anhydride, baking soda, and aniline — all requiring alcohol to produce, meaning the sulfa drug is nearly within reach. Kaseki then informs them that the winner of tomorrow's Grand Bout will receive abundant alcohol from the village, making the tournament crucial. The group meets the priestess Ruri, who collapses from illness and nearly says something significant to Senku before being carried away. Magma, overhearing, coldly remarks that Ruri may die on her own after their marriage. Chrome, furious, challenges Magma and reveals he has been secretly training to strike at weak points. Senku's team strategizes to rig the tournament bracket, but the draw goes completely against their wishes, placing Kinro directly against Magma in the first match. **Finally:** Senku responds by preparing a science-based performance-enhancing drink for Kinro. During the match, Kinro struggles against Magma due to his poor eyesight. Suika, having escaped being tied up by Mantle, rushes to deliver Senku's handcrafted glasses to Kinro mid-fight. With his vision restored, Kinro dodges all of Magma's attacks and defeats him decisively, declaring that science had