Spirit's Place

 is Track 18 on the Xenosaga THE ANIMATION Original Soundtrack. It plays in the following scenes:
 * Shion first notices Kirsch aboard the Woglinde in Episode 1.
 * Shion remembers Kirsch when talking with MOMO in Episode 3.
 * Ziggy breaks MOMO out of her cell on Pleroma during a flashback in Episode 4.
 * Kirsch reaffirms that her actions are her own will to Albedo and herself in Episode 9.
 * Virgil saves MOMO in the Kukai Foundation in Episode 9.
 * Albedo searches for the Y-data inside MOMO in Episode 11.
 * Kirsch recognises Shion in Proto Merkabah in Episode 11.
 * Kirsch is taken by Albedo and works with him in a flashback in Episode 12.