Tsukasa has learned about the cave where the nitric acid is collected. The race is on between Senku and Tsukasa to restore humanity in their respective visions.
They must have gone 
extinct right off the bat.
.لا بدّ أنّها انقرضت من البداية
Es gibt sie nicht mehr.
Debieron extinguirse pronto.
Debieron extinguirse pronto.
… qu’ils ont dû vite disparaître.
Si saranno estinti praticamente all'istante.
Elas devem ter sido extintas na hora.
Она почти сразу вымерла.