That was fucking incredible!

Harry August is an Ouroboroun, a member of an immortal subtype who live the same life again and again. Ouroborouns have organized their shadow society under the banner of the Cronus Club, which exists to aid their members through the first few agonizing "wait, what?" of their repeated lives, and aid their members through the boredom of a childhood where they already know everything and then escaping the disaster of history. The Cronus Club is a kind of anti-illuminati, self-policing members to avoid meddling in history.

But then a message is passed down through time, a young child appearing at the deathbed of a member to say "The world is ending, the future is shortening, and we don't know why. Please stop it." While Ouroborouns are difficult to kill through linear means, they can have their memories erased, losing centuries of knowledge, and can be eliminated permanently by preventing the circumstances of their birth.

The first half of this novel is a leisurely exploration of the Ouroboroun existence, the second a rocket of intrigue with Harry matched up against another member of his clade who wishes to create a device called the quantum mirror, a machine which will give perfect knowledge of the universe. The man who is creating the mirror needs technology far in advance of his time of the late-20th century, and his meddling may be driving the end of history. This novel was too good to blemish the review with spoilers, but I greatly enjoyed it.