Huey and Webby’s disagreement over the existence of a mythic species leads the kids to explore an eerie abandoned subway tunnel, while Mrs. Beakley grows suspicious of Lena.

With Huey’s and Webby’s help, Fenton woos a punk-rock scientist, Gandra Dee, only to uncover her dangerous plans for Gizmoduck.

Scrooge reteams with his conniving ex-partner and old flame, Goldie O’ Gilt, to find a long-lost golden lagoon, but Glomgold has other plans.