Your exploring an unknown Enclave base, and all the occupants are dead. You have to find out how. The base is quieter then a church mouse. Lame so far? Heres where action fits in. You come across various holotapes of dead soldiers/families. After you listen to it, the screen fades, and you go back in time to that persons shoes to see what really happened. A mix of exploration and story development (similar to Vault 11), with lots of action in between in the boots of various characters.
It doesn't have to be Enclave, I just like wanted to get the game mechanic out there. Piecing stories together by playing through others experiences.