Here is a sampling of the thoughts that drive Henry through the day as we the readers follow along with him. 

San francisco, california

The day, and novel, are driven by the need for Henry Quantum to purchase a last-minute gift for his wife.

Twin Peaks, San Francisco

Preparing to leave for his typical workday, Henry realizes that "the twenty-third of December had arrived without the purchase of anything at all, not even a stocking stuffer, he knew he had no choice but to go shopping."