WARNING: The following article contains spoilers for Dr. Stone Chapter 144, by Riichiro Inagaki, Boichi, Caleb Cook and Steve Dutro, available now from Viz Media.
At the start of the current arc of Dr. Stone, Senku and his allies set their sights on the moon, where the mysterious Whyman responsible for the petrification of Earth is located. Their first order of business has been to head to the United States to kickstart corn production and thus create the alcohol needed to make more revival fluid.
However, Senku and Ryusui -- the captain of the Perseus -- disagreed about the best way to get there in Chapter 143. Ryusui wanted to take the longer, but safer, route. Still, the delay would have meant waiting until after winter to start their plans. Senku, conversely, believes they'll be able to get to America faster using the Great Circle Route, which is markedly more difficult. So the two decided to resolve their differences with a poker showdown.
In Chapter 144, Gen, who supports Ryusui's plan, works the ship's captain to beat Senku and Kohaku, who uses her fantastic vision to stop all of Gen's tricks before he can pull them. Eventually, Ryusui gets just the cards he's looking for and goes all in with four aces, one of the strongest hands in poker. Senku and Kohaku are fairly convinced Gen cheated to give Ryusui the cards he needed, but they were too distracted by his antics to catch him in the act.
Still, Senku calls and trades in three of his cards. It's enough, though, as he ends up with a royal straight flush, the highest possible hand in the card game. The onlookers choose to ignore the fact there are now five aces on the table, which is more than should be possible, and instead the action turns to just how Senku accomplished the feat.
Earlier in the arc, Chrome bragged about a device he had that carved sound into "a lacquered wooden tube." From that tube, Senku extracted the chemical urushiol. He'd spend the game marking the edges of certain key cards with the invisible, colorless chemical. However, actually sensing when urushiol was present relied on Senku's sensitive skin. Although the genius has won the game of cards and will now get the United States faster, he's left with a swollen face due to his allergic reaction.
Dr. Stone Chapter 145 releases March 29 from Viz Media.