Annihilation

No one knows what year it is, granted there is almost no one alive. An atomic war lead to the complete destruction of the entire world, with very few, and scattered, survivors. Civilization can't be rebuilt; but there are those who will strive for the impossible.
Shenzi, an eleven year old boy, is almost certain that he is the last person on earth, and yet he is determined to survive as long as he can.
Alek, a twelve year old girl with a dream; a dream about a young boy on his own, halfway across world. She knows where he is, and she is determined to find him and bring him to safety in her secluded group of survivors.
What will they encounter on their long, hard journey of primal endurance?