Eternal calm is a prologe to 10-2......here's some info about it. this information is provided by FFShrine......

The Eternal Calm was shipped as a bonus on Final Fantasy X: International + Last Mission. Since the disc was really only available in Japan, most US (and European) gamers never had a chance to see the cutscene. It served as both an added bonus to Final Fantasy X, and as a precurser to Final Fantasy X-2.

Although much of the Final Fantasy X-2 storyline ties directly into Another Story, Square didn't publish it along with the release of Final Fantasy X-2. However, it did make a debut in the US through OPM magazine; the cutscene was delivered as a bonus for the magazine. Again, most gamers missed out. For the first time, the movie was actually available with (official) English dialog and subtitles.

Eternal Calm: Final Fantasy X-2 prologue

This info is already a bit outdated, isn't it? It was big news when... a year ago? But now it's just...

I think the European version of Christal Chronicles has the Eternal Calm, wasn't that the case...?

a year ago!?....i guess im a little out of date....i didnt know...we had no sign of it here in the UK.....ive never heard of it here sorry...i just seen it on shrine and thought it looked interesting...

The eternal calm cutscene is also an extra added to unlimited saga, although I wouldn't recommend buying unlimited saga.

Yes, whatever you do, don't buy Unlimited SaGa.

At any rate, I have a copy of Eternal Calm that was on a X-2 demo disc.