"As above, so below."
There's a solemn tone in the man's voice as he pulls the pentacle amulet off his neck. For a moment it would simply lay in Harry's hand... Before it begins glowing with a blue light, one of the ends pointing in a direction as Dresden begins to follow it. He'd walk out the doors and follow the spell, finally being lead to a scooter parked not too far away and digging around under the seat for a moment. After a bit, he returns with a copy of JUMP in hand and a sly smirk on his face as he hands it off to Gintoki.
"You left it under the seat of what I assume is your scooter, forget it or was that there for a reason? Either way, job's done and now I believe I've proven my skills. No-"
He's cut off by the entry of Sayaka, not from around here, fancy dress, and tossing around illusion magic of some kind? This girl is far more than she appears to be at first glance... And yet clearly lost, well it's a good thing she's come to him rather than... Less savory types, not everyone would just help out some girl who's tossing around magic, juicy sort of person to use by some standards.
"Those are some neat spells you've got there, name's Harry Dresden, Wizard. And I'm guessing you've gotten lost or something? Well, I can help out with that, though uh a name of both you and them might be useful first. And I could always use a bit of blood for some old-fashioned wizarding if need be!"
He'd offer the young woman a friendly smile, clearly evading eye contact with her despite that... He assumes she'd know why, though no telling with all the weirdos he's met lately, maybe she's a "Persona User" rather than a Wizard? Either way, Dresden's tone is notably kinder as he speaks to Sayaka.