what kind of wedding has a passphrase and response?

Okay, I thought it was weird when your wedding invitation was slipped to me in a microfilm canister, but I’ve been on this train streaking through a barren European landscape for 3 days now, pursued by armed men with serious mustaches, and as I’m climbing on top of the lead car to leap off a bridge to safety, I’m starting to think think maybe that wasn’t a wedding invite.

Anyway, please disregard my RSVP, which will self-destruct in 10… 9…