Henry and Casey were in Spikemuth, same with Piers, Professor Magnolia, and Marvin.

Henry and Casey decided they'd wander for a while and notified Piers.

Piers: Alright, well, you two be safe, I know you're capable of handling yourselves, but be safe.

Henry and Casey would nod before exiting Spikemuth and wandering to whatever they find interesting or where they just want to go in general.