The very first episode of Angel, and one that brings together the main characters for the first season, City Of is the beginning of a great struggle for the vampire. Angel has moved to Los Angeles, and as the episode starts, we see that he is hunting vampires, and keeping watch over the city people. He then meets a half-demon, Doyle, who makes him realise that although he is helping people, it is a difficult mission with no guide and no clear direction.

Doyle tells Angel of the visions he gets from a mystical force called the "Powers That Be". He suggests that together, the two of them could make a team to fight evil. The visions Doyle receives are of people in trouble, so together, they can seek out evil and defeat it. Their first mission together is for a girl in trouble at a coffee shop, but little else is known.

As Angel investigates, he meets Cordelia, and old friend from Sunnydale, and also a nasty vampire who has been luring women towards him. Although he is too late to save the girl in Doyle's vision, he manages to rescue Cordelia after she has been invited to a "special" meeting with the vampire.

As the episode ends, it becomes clear that Angel, together with Doyle, and now Cordelia, will fight together, as a paid organisation, helping the people of Los Angeles.