Si Biao is an agent with Chinese Intelligence.
He would probably smile at that, true though it is. Biao really considers himself a simple man from simple beginnings wanting little more than a simple life. Life being as it is, of course, he is not going to get it but the road from where he was to where he arrives is an interesting if not explosive one.
In the world that Biao inhabited, China was involved in a quite large war between Pakistan, India, and China over the Kashmir region. All three nations have claimed that area for centuries and the arguments finally lead to conflict and young men are needed at the battlelines and Biao is one of thousands to be called up.
This we learn early on as well as the fact that surviving it will get him posted in a Pakistan largely controlled by China and then, through a set of events quite interesting to follow, he gets noticed by Chinese Intelligence and instead of returning the life he had hoped to live, he is pulled in places he had never heard of to do things he didn't always understand.
Biao is from a very, very poor family who, according to his father, had been poor for generations and would likely continue to be so for many more. That is the attitude that Biao takes with him as life is constantly changing around him but no matter what transpires, it seems that Biao is both the poor sap stuck at the bottom and the incredible survivor who manages through luck and tenacity to make it out again.
When he finally, after a very long sequence of events, is pushed into Intelligence work, it is with a group that calls itself "the Nothing", which will send him to various places in the ever-growing global war.