[ It's a threat, sure, but it also makes him laugh. Genuine, and a little sardonic, and fond.

They're both liars, so Akechi has no reason to take what he says now at face value. Maruki knows that. He says it anyway, eyes alight with his total honesty. ]

I can assure you that if we return to our reality with our memories of this place intact, I don't plan to breathe a word about you.

[ He hasn't actually thought about it this way before, but... ]

I guess I see what's happening to us here as... a closed circuit, so to speak. One where you have my promise of total confidentiality, which carries over into our reality or, god forbid, any other one.

[ It's so simple, really. It just took a spin in the labyrinth to crystallize it in Maruki's mind.

He smiles at Akechi. ]

You're my ally. I'll maintain your image.

[ Not a threat. A promise. ]