WARNING: The following article contains spoilers for Season 1, Episode 13 of Dr. Stone, "Masked Warrior."
Things are going all Breaking Bad in Dr. Stone now that Senku has a fully fledged chemistry lab, as well as the essential, chemical ingredient that he acquired in the last episode: sulfuric acid. "Time for mad chemical cooking!" Senku excitedly tells his Kingdom of Science acolytes in the anime's latest episode. Their ongoing quest to engineer a cure-all drug for Kohaku's sick sister, Ruri, hits another roadblock, however, when Senku realizes they're missing another vital element: alcohol, something that would take a huge amount of time and effort to make from scratch.
Wouldn't you know it, though? The winners of the Grand Bout, craftsman Kaseki informs him, are showered with celebratory booze -- the very Bout that the team have been preparing Kinro and Ginro to compete in to save Ruri from having to marry its would-be, brutish victor, Magma. And, guess what? The Bout is going to take place the very next day. As Senku himself says in a fourth-wall teasing way: "The timing is too perfect!"
The plan to secure Kinro's place as the Bout's winner is simple: they're going to cheat. By entering as many combatants from their side as possible -- namely Kohaku, Chrome and Ginro -- the Kingdom of Science hope to tire Magma out before he goes up against Kinro in the final round. Even Senku is going to enter the tournament, much to Kohaku's surprise as the young scientist isn't exactly known for his physical prowess. Just to massage their odds even further, Senku also whips up the Stone World equivalent to an energy drink: caffeine for alertness; honey for blood sugar and sweet flag to keep you cool.
The day of the Bout is the first time -- after six months of waiting -- that Senku is granted access to the village that his companions come from, which triggers a strange event before the contest starts. Ruri, upon hearing Senku's name, emerges from her quarantined quarters to talk to him. She's convinced she somehow knows him despite the pair having never met before, leading her to prompt him for his last name. This strikes Senku as strange because her village has no such tradition of giving surnames. Before she can say what she thinks that surname is, though, she succumbs to a coughing fit. We'll have to wait for this new mystery to be revisited another time.
When the Grand Bout kicks off, all of the Kingdom of Science's carefully laid plans immediately fall apart when Kinro and Magma are paired up for the very first round. Thankfully, all of Kinro's months of training alongside Ginro and Kohaku pay off as he goes toe-to-toe with Magma from the get-go... Only to then nose-dive when Magma steps further back from the village guard and we're reminded of Kinro's near-sighted problem.
With his opponent reduced to a blurry shape in front of him, Kinro is struck down by a volley of vicious blows from Magma's staff. Only Suika, who suffers from the same thing, realizes what needs to be done. Springing into action, she launches her watermelon hat onto Kinro's head. The lenses Senku installed in it work perfectly, allowing the warrior to get back onto equal footing and bring Magma to his knees.
New episodes of Dr. Stone air every Saturday as part of Adult Swim's Toonami block, and on Crunchyroll.