Attack on Titan: Before the Fall Vol 6

ON THE SHOULDERS OF TITANS Fifteen years ago, humanity led a last-ditch attempt to discover the Titans' weakness – a survey expedition to capture one of the beasts. But the ten-meter Titan who appeared during the capture attempt threw the expedition into chaos. Among those who escaped behind Wall Maria was the genius craftsman Angel, a weapon-developer who was participating in the expedition as a researcher. What would he conjure up from this failure?

Source: Penguin Random House API