The Hollywood Spiral

From the author of Apathy and Other Small Victories, this darkly comic novel set in the near future about the race to find a missing cyber program with the power to bend reality—all before a fast-approaching comet destroys the earth.
  In the near future, after the internet grinds to a halt amid a wave of cyber-attacks, a company named Zodiac steps in to replace it with an evolved, augmented-reality version called The Grid.  Harrigan, a hard-drinking private detective living as off-Grid as possible, is about to be evicted from his apartment when a stranger shows up asking for his help in finding Anna, an escort who he claims he's desperately in love with. Turns out that through Harrigan's new client, Anna has come into possession of a program/entity called Mirror, Mirror, which has the capacity to merge The Grid and reality, bending both to the whims of the program's user. Soon Harrigan finds himself up against the last surviving organized crime gangs in Los Angeles, Zodiac's mercenaries, and a mysterious group called The First Church Multiverse, all of whom are hot on the trail of Mirror, Mirror—if the comet rapidly approaching Earth doesn't kill them all first.