| Album | Wild Arms the 4th Detonator Original Score |
| Composer | Masato Kouda |
| Disc | 2 |
| Track | 3 |
| Length | 2:52 |
| Instrumentation | Snare drum, cymbals, castanets, violin, viola, trombone, chime |
| Previous Track | From Anxiety to Impatience |
| Next Track | Weapon X |
REASON Which Opens the Moment (Japanese:瞬間（いま）を拓くREASON)[1] is a song used in Wild Arms 4 when the player party is lured onto the Aerial Fortress Eulalia from White Orphanage after being pursued by Jeremy Non, and Kresnik Ahtreide arrives to protect his sister Yulie Ahtreide from Jeremy's attempt to murder them. It is only during this scene that the voices of the members of the CABAL in charge of Brionac can be heard as they plot to capture Yulie and use her to realize their ambitions to control Filgaia.