"I don't remember any such passage in the invitation... You mean there is a cipher hidden within it?" Welt furrowed his brow.
"That is the intriguing part. The invitation sent by The Family is a music box that plays a melody when you wind the key. But the one in our hands is somewhat strange... The background music has some discordant notes mixed into it."
"I transcribed those noises, and their frequency matches the gravitational wave frequency during an Astral Express warp jump perfectly. Using the spatial curvature of the train engine as the key—I got the message above."
Chapter 153