The Encounter

The whole world was facing crisis because of demons or rather aliens from another galaxy who wanted to take over our galaxy(Milkyway galaxy)and especially Earth.They wanted to take over humans and humanity.They thought if they took over Earth they can take over whole galaxy because in their view Earth was the strongest planet in the galaxy.
So, indirectly the safety of whole galaxy was on the shoulders of Earth.
But the current generation of Earth knew nothing about it.