Chicago P.D. and Chicago Med have a family connection in the form of Jesse Lee Soffer’s Jay Halstead and Nick Gehlfuss’ Will Halstead, and Jay has dropped by Med often enough that Med almost created a super weird love triangle involving the brothers and Torrey DeVito’s Dr. Natalie Manning.
And there’s still one more example of P.D. expanding the Dick Wolf universe, and the next one is a big one.
Will also debuted in One Chicago as Jay’s brother on P.D., so the ties are pretty much as tight as possible for two lead characters on different shows, especially now that Gabby and Antonio Dawson are both gone from Chicago Fire and P.D., respectively.