Ruins

When the world is threatened by aliens called Terainians, can 13 teenagers save it from falling into ruins?
7 are half Terainian.
6 are all human.
The humans don't know the 7 are half bloods.
What's more, the most powerful Terainian in existence is in their midst.
How will they react when they find out how easily the end could come, should one person "simply" say yes?
Let me ask you this:
Are you afraid of the big, bad wolf?

Feedback is greatly appreciated, and I'll add more whenever I can.
I hope you enjoy it :)