Dick Wolf Thinks This One Chicago Character Made Television History

When legendary television producer Dick Wolf helped bring "Chicago Fire" to the airwaves in 2012, he was no doubt hoping he had another "Law & Order" level hit on his hands. Little did he know, the series would serve as the gateway to a full-blown small screen franchise, whose shows — aside from the short-lived misfire "Chicago Justice" — regularly rank among television's most watched.

Dubbed the "One Chicago" franchise, the two series rounding out the lineup are the medical drama "Chicago Med," and the procedural thriller "Chicago P.D." If you're a "One Chicago" fan, you know the franchise has become renowned over the years for being a shared narrative universe whose characters move from one series to another when storylines make it possible. This ingenious narrative tool has so far led to dozens of thrilling crossovers on NBC, and all but ensures fans of any "One Chicago" series will check into another whenever their favorite characters appear.

You may not realize it, but Wolf took the "One Chicago" crossover approach to the extreme in March of 2020, and in doing so, he believed that one of his "Chicago P.D." characters made television history.

The character in question is "Chicago P.D." standout Detective Hailey Upton (Tracy Spiridakos), who joined the intelligence unit late in the series' fourth season and fast became a fan-favorite character. Like her "Chicago P.D." castmates, Spiridakos promptly joined the "One Chicago" crossover fun, making notable appearances as Upton in the other "One Chicago" shows. By then, some of her costars had actually crossed over to NBC programs outside of the "One Chicago" universe as well. 

But for a 2020 crossover event, Upton bested them all by turning up in a series that airs on another network entirely. The show she jumped networks for was, understandably, another of Wolf's productions, with Upton making a memorable one-off appearance in the CBS hit drama "FBI." Wolf announced plans for the crossover event in 2019, claiming, "to my knowledge, it has never been done" (via The A.V. Club). Unfortunately for Wolf, it's hardly the first time a character had crossed network lines to appear on a show. 

While it's still quite rare for competing networks to share anything content-wise, characters from The CW's "The Flash" actually appeared in CBS' "Supergirl" long before Wolf's "Chicago P.D." and "FBI" crossover, while another DC character, Lucifer, from the show of the same name on Fox and later Netflix, also appears in The CW's Arrowverse. Likewise, Fox and ABC crossed over with legal dramas "Ally McBeal" and "The Practice" for a case in 1997. While this doesn't make the "Chicago P.D." and "FBI" crossover any less compelling, it's far from the groundbreaking event Wolf believed it to be.