The book opens in Mexico City in the future, where sometime assassin Axl Borja is about to try to make one last hit, which goes drastically wrong when he takes three rounds to do the job.

Losing his gun in the process, he is caught by the police, and throws himself on the mercy of the Cardinal Santo Duque - his former boss, a minister of the Vatican, and someone given to unusual methods of revenge.

Axl's mission is to track down the late Pope Joan (specifically, a data-holding bracelet of hers), who drained the Vatican's immense assets to buy aid and other kinds of support for the Third World before being apparently dismembered by a horde of the people she helped save.

As a man responsible for much of the ringworld's population, the Cardinal can't send an agent officially, so he tortures and seriously injures Axl - fitting a ceramic neural-interface port into his head, removing both his eyes, and running him through a set of SQUID probes designed to pillage what's left of his memories.

Axl's eyesockets are filled, first by a "plug-and-play" Red Cross-issue eye, so cheap it only works in black and white and very low-res; and later by a more complex eyeball capable of night-vision and with a digital counter in the corner to remind him of his deadline.