Slugterra (2012)

S4E3 Into the Shadows: Out of the Shadows (3)

After the confrontation with the Shadow Clan, Tad has gone missing, prompting the Gang to head out without him to look into the recent reports of disappearing slugs. As they follow the clues, the investigation takes a surprising turn, revealing that the path of the missing slugs leads them directly to Dr. Blakk's former lair!