Taken from the website of the publisher:
While hunting for loot in the ghost world, your crew was sold out. You've walked right into an ambush, with hungry Wraiths on your heels.
QUESTIONS YOU WILL ANSWER AS YOU GO.
Why does your crew need loot? What ghost powers does your particular crew member possess? What is the ghost world? What are Echoes? What are Wraiths?
GHOST/ECHO is presented as an 'oracle game'. It provides only a starting point and a resolution mechanic. You and your friends fill in the rest of the details as you play.