Mysterious World

 is Track 1 on the Xenosaga THE ANIMATION Original Soundtrack. It plays in the following scenes:
 * Jr. and Gaignun discuss KOS-MOS, Shion and MOMO in Episode 6.
 * The party attempts to communicate with Kirsch before fighting the E.S. Simeon in Episode 12.

The piece's melody is based upon a motif from Xenosaga Main Title.