Mecha Mutiny Slugterra : Season 1 Episode 7

The gang is out hunting a very speedy slug when during the chase their mechas malfunction. Back at the hideout Kord tries to figure out what the issue is but can't. He thinks it might have something to do with the new upgrades he got from his friends back at the forge(a factory of mecha beasts) so they head there to have it checked out. When they get there they find that the cave trolls that run the place have been captured and replaced by blacks men who are attempting to corrupt the cores of the mechs.