Singularity Sky by Charles Stross is a fun combination of a strong AI and a espionage novel. Stross takes us years into the future where an advanced being has change the path of humanity and set down rules that humanity can not break. The book deals with the impact of technology on civilizations that try to suppress technology.

Somewhere along the way, a singularity happened and a being, which calls itself the Eschaton, appears. It splinters humanity among the stars. For various reasons, it allows faster-than-light travel, but forbids violating causality. Earth is one of the stronger civilizations and has a United Nations that enforces the Eschaton’s causality rule out of enlightened self-interest (i.e. they’re afraid of getting caught in whatever punishment the Eschaton metes out to whoever breaks the rule). Rachel Mansour is an agent of the UN, who is investigating whether or not the New Republic empire is attempting to violate causality. She encounters Martin Springfield, an engineer who was hired to upgrade New Republic spaceship engines and is an agent of the Eschaton.

The New Republic empire is fairly luddite (compared to other civilizations) and has run into a problem. One of their colonies ran into a traveling trade show that gives away advanced technology to anyone who can entertain them. Revolutionaries on the colony use the new technology to over throw the existing government. The New Republic is attempting to use the faster-than-light engines to arrive at the colony before the traveling trade show and prevent the overthrow. Rachel and Martin are dragged along for the ride and have to prevent the New Republic from violating causality.

Stross does a great job of taking a futuristic society and showing the impact of even higher levels of technology on society. And the espionage adds a bit of fun to the novel. Overall an amazing debut novel for Stross. Highly recommended