The Discovery

Perhaps humanity arrived on the galactic stage to late.
Maybe when we take our first steps beyond our ancestral home we will find a universe in decay. Striding in the footsteps of giants long gone.
If this is the case, if humanity finds only ruins and artefacts left by civilisations who long ago had their time in the sun. What might they leave for us? Could we find tools to help us prosper, or the weapons that lead to our destruction?