Dr. Stone Wiki
Dr. Stone Wiki

The Age of Energy (動力の時代 Dōryoku no Jidai) is the twentieth episode of the Dr. Stone anime.


Tsukasa plans a second attack after a few months of preparation. He has no idea what Senku and his kingdom are cooking up in the meantime.

Plot Details[]

Gen impersonating Tsukasa

Gen impersonating Tsukasa.

Senku and Gen start to think about what Tsukasa will do. They can perfectly predict what Tsukasa is thinking. Tsukasa knows that in time, he will gain bigger army, but it will take time for Senku to create more gunpowder and other weapons. Given that their fortress is on an island in a lake, they have the defense upper-hand and it will be hard during winter. Tsukasa tells Hyoga that he will place men watching Taiju and Yuzuriha in case they are spies and is concerned if Senku decides to attack preemptively. Hyoga tells him he left Homura watch over Ishigami Village but finds it ironic that they lack communication technology, which is needed in such war. Tsukasa decides they attack after winter ends, with Senku guessing their time limit is spring.

The girls trying cotton candy

The girls trying cotton candy.

Chrome and Kaseki are wondering how the phone works and Senku explains that the voice creates vibrations which pointed at diaphragm, create small electrical current in rhythm with the vibration. Using a vacuum tube, they increase the current power. Sending it around and around in a circle creates radio wave and the listening side does the opposite and receives the message. As first step into making phones, they need to create cotton candy machine. Creating the machine, Senku explains that putting sugar and rotating it, causes small sugar threads to come out. But if they replace the sugar with gold, they will get gold threads. As gold is precious, Senku decides to test it with sugar first.

Homura trying cotton candy

Homura trying cotton candy.

They take sugar crystals from the burnt wine in the village. They make cotton candy, and the villagers end up loving it as its their first time tasting a food like that. Senku asks Gen what type Homura is, with Ginro guessing Senku is interested in her romantically, but Senku explains she is watching them. Gen explains that Hyoga only trusts her; she follows his orders, and it is unlikely that she will betray him and join them. Senku makes a stand closer to Homura and leaves cotton candy. The others wonder why he did it, and Senku reveals that it may help make her join them. Ruri guesses he also just wanted to share cotton candy with a girl. Initially, Homura refuses to eat it, but recalling how Hyoga told her that they wouldn't leave anyone behind, she ends up tasting it.

Ginro using the gear

Ginro using the gear.

Ginro can't understand why Gen and Senku are discussing the balance of the cotton candy, but they explain it had lumps, which means the gold will also have lumps, and they need to find the reason and fix it. Making cotton candy again, they see that the rotation speed drops when the ropes change, and that causes the lumps. Unable to use more people as the winter is coming, Senku decides to make gear. He finds Kohaku's shield to be perfect for that, which causes Kokuyo to recall how he won it and gave it to his daughter but believes it will be precious to Kohaku as he gave it to her; however, Kohaku doesn't think twice and immediately agrees to use the shield as gear, crushing Kokuyo's soul. Seeing the gear in action, Chrome gets an idea and shares it with Kaseki, which super excites him. Senku reveals that the wire needs to be long enough to reach the top of the mountain, which shocks everyone.

After three days of work, Chrome tells Senku that he is ready. Senku is surprised to see they made a waterwheel without any knowledge about it. He immediately combines it with their generator and creates a hydroelectric power plant.







Inventions and Discoveries[]

  • Cotton Candy
  • Gold Thread
  • Waterwheel/Hydroelectric Power Plant

Anime to Manga Differences[]

  • When Senku explains how long the golden wire needs to be, in the manga, it is to Kohaku, Suika and a bunch of other villagers. In the anime, the random villagers have been removed and it is with these two plus Kokuyo, Kinro and Ginro.
  • The anime omits Suika's line about she and the other kids helping with the thread since the adults are busy preparing for winter.



Site Navigation[]

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Story Arcs
Prologue Saga
Stone Formula Arc
Chapters 1234
Episodes 12
Vs. Tsukasa Arc
Chapters 56789101112
Episodes 345
Ishigami Village Saga
Kingdom of Science Arc
Chapters 131415161718192021222324252627282930313233
Episodes 5678910111213
Village Games Arc
Chapters 34353637383940
Episodes 131415
Village Origins Arc
Chapters 4142434445
Episodes 1617
Stone Wars Saga
Vs. Hyoga Arc
Chapters 4647484950
Episodes 1819
Communications Arc
Chapters 5152535455565758596061626364656667686970717273747576777879808182
Episodes 20212223242526272829303132333435
Source of the Petrification Saga
Age of Exploration Arc
Chapters 8384858687888990919293949596979899 100
Episodes 35Ryusui3637383940
Treasure Island Arc
Chapters 101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138
Episodes 4142434445464748495051525354
The Truth of the Petrification Saga
New America City Arc
Chapters 139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169
Episodes 555657
South America Arc
Chapters 170171172173174175176177178179180181182183184185186187188189190191192193
New Stone World Arc
Chapters 194195196197198199200
Globetrotting Arc
Chapters 201202203204205206207208209210211212
Stone to Space Saga
Moon Mission Arc
Chapters 213214215216217218219220221222223224225226227228229230231232