Not A Hero

Jim King is not quite a midget. He has just been laid off from a job where he was doing well. He then gets a job from a help wanted ad, posted on the front door of a business.
Jim then works hard and smart. He does worry about his new job, because large strong looking young men check in and never seem to check back out.
One day, the Office Manager tells Jim that they need a guy to undertake a job that will pay a year's wages for a day's work.
Jim doesn't believe that someone would pay a year's wages for a day of his work. However, the work is, 'Just out the back door here. Also the company will arrange for Jim to gain an inch and a half in height.' Jim isn't a hero but he's hooked!
Jim is then sent to retrieve an, 'object.' The work is hard and done at the risk of his life, but Jim thinks and struggles through and comes back with the object.
Then the adventure begins.
Jim is sent on more missions to retrieve mysterious objects. Each mission is difficult and done at the risk of his life, but Jim thinks and struggles through and comes back with the object(s).
Gradually, Jim comes to realize that he's involved in something beyond his understanding and that the objects are each some sort of linkage to a very powerful being.
Jim could cut and run, but he refuses to abandon his, 'companions of the journey.'
Eventually, Jim is abandoned in a hostile world, by his employer. Jim's only hope is to help one of the beings that he retrieved, as an object, to arrive at the mysterious Day of Reckoning and a final adventure.