In just three years, CEO Robbie Case has grown Core Communications, a data technology company, from 30 people to over 5,000. Now a $20 billion company made legendary by its sudden success, Core is based on a technology no other company can come close to copying, a revolutionary breakthrough known as "drawing blood from a mainframe." And Robbie, its 35-year-old CEO, is acclaimed worldwide for his vision, leadership and wealth. Except that all of it is based on a lie. The technology doesn't work, the finances are built on a Ponzi scheme of stock sales and shell corporations, and Robbie is struggling to keep the company alive, to protect the friends who work for him and all that they've built. Each day, Robbie tries to push the catastrophe back a little further, while his employees believe that they are all moving closer to "grace," the day their stock options vest, when they will be made rich for their faith and loyalty and hard work. The details of the lie are all keyed into a shadowy interface that Robbie calls Shimmer, an omniscient mainframe that hides itself, calculates its own collapse, threatens to outsmart its creator and to reveal the corporation's illegal, fragile underpinnings. Shimmer is the story of a high-tech crusade nearing its end. The shell game Robbie has created is finally running out of room.