Chapter 139

Bone-Chilling! The Underground Labyrinth (!!) is the one hundred and thirty-ninth chapter of Kohei Horikoshi's My Hero Academia.

Summary
Sir Nighteye and Fat Gum's groups have charged into the Eight Precepts of Death's Headquarters. Lock Down has a bad feeling since something is wrong due to them while Shota assumes that since Kai Chisaki has not shown himself, he must be in the basement evacuating everything to hide which includes Eri. The Heroes reach a shrine with a vase on it; Sir Nighteye removes the vase and pushes on a wooden panel, which causes a door to open. Suddenly, yakuza members of the Eight Precepts of Death appear and prepare to attack. Shota Aizawa disables their Quirks with his Erasure while Bubble Girl and Centipeder apprehend the yakuza members. The rest of the Heroes go ahead while Bubble Girl and Centipeder continue to apprehend the yakuza members.

The Heroes head down towards the basement, but are surprised to see a wall before them. Mirio Togata uses his Quirk to phase through the wall, with Tamaki Amajiki explaining that Mirio's Hero Costume is made with special fibers from his hair, allowing his clothes to phase with him. Mirio has phased through the wall and sees that the path stretches on like Nighteye said. Mirio returns and tells the Heroes that the wall was thrown in the way to block them; Lock Down suspects that it was Chisaki's Quirk that put the wall there in the first place. Izuku Midoriya activates One For All: Full Cowl and Eijiro Kirishima activates his Hardening. Using their enhanced might, Izuku and Eijiro shatter the wall together.

Having shattered the wall before them, the Heroes are surprised to see that the pathway has become distorted and warping. Fat Gum believes that this is the work of Mimic's Quirk, Mimicry, which allows him to enter objects and control them freely, but is in disbelief that he can freely control an entire basement. Fat Gum asks Shota to disable Mimic's Quirk, but Shota is unable to since he cannot see Mimic's body. Tamaki surmises that Chisaki is stalling them for time to hide everything and escape and starts becoming stressed out since their lives could be at stake. Mirio encourages Tamaki by saying that they will definitely rescue Eri. Mirio decides to go on ahead and phases through. Tamaki starts blaming himself for falling under pressure. Although he cannot stop Mirio's phasing Quirk, Mimic is confident that even if he does reach the end Mirio won't be able to do anything by himself.

Mimic causes the floor to open up beneath the Heroes, causing the heroes to fall down a single floor. The heroes are in a hall; three figures appear from the dust, revealing themselves to be three members of the Eight Expendables. As Fat Gum prepares for battle, Tamaki decides to battle the three Eight Expendables himself in order to make up for falling under pressure.