[rdouglass]

Well, you cannot totally ensure your race will survive but it would help if you never went home. If you never went home, the alien (or alien tech) could not track you back to the home system.

Of course you're never sure whether or not the alien scanned and read all records in the computers of your ship, used mental telepathy on you, read the warp point signatures on the quantum singularity, or other such hogwash. So without knowing the 'bounderies', you can't really know the solution.

But the best solution would be to blow each other and the nebulae up.