Once more: My Mac screwed up in flipping photos. The photos were at the time stored

[phantasticphotog]

on a 250GB Lacie external.? Flipping photos needed for evidence, I tried to save the action. There was almost no room on the mac, which could not complete the action. The photos looked like they disappeared. But, the storage data of the external did not decrease. A friend tells me the photos are still there. How do I retrieve them? I need to get the data before it gets written over with data.

How do I get my data back?