Yorick Brown was an amateur magician/escape artist in love with his girlfriend, Beth, and training the monkey Ampersand, to do domestic chores for quadraplegics, when the plague hit. Every male creature on Earth died a sudden, bloody death simultaneously one day--except for Yorick and Ampersand. Yorick sets off to find Beth, who is in Australia, meeting up with Agent 355 of the secret Culper Ring and cloning expert Dr. Allison Mann, both of whom see humanity's last hope in Yorick.

Yorick's attitude is characteristically witty, and he often prioritizes opportunities for clever quips over his own safety. It is later revealed that Yorick in fact has something of a death wish when a former Culper Ring agent and friend of 355 interrogates him in a seeming S&M domination scenario. This reveals some of Yorick's underlying depth, as do his apparent hang ups about sex in a seeming paradise of willing women.

It has been revealed that the only reason that he has survived the plague is that he handled his pet monkey Ampersand's feces (who was a former test monkey) and gave him a resistance to the plague.

He has also fathered a daughter since the plague hit Beth Jr.