Secrets and Horrors/Locked Dead

Season 1 (Secrets and Horrors), Episode 1 (Locked Dead).

Story
Post Office Pen: Ummm... where are we?

Pixel: Subway. We both slept here, so... I don't know? Let's go to the mall.

'Pixel and Post Office Pen go to Oakland Center'

Dress: Hello, guys.

Metal Door: Who?

Dress: Not you.