The One Chicago universe offers fans seemingly endless entertainment, from dramatic plot lines to tender relationships between characters.

And the drama extends beyond the confines of single shows.

The shows' premises are fairly easy to guess, given their informative titles.

Amy Morton and Christian Stolte

But when they work, Chicago love storieswork even when the characters come from separate shows.

But even a short-lived romance can do something for fans.

A perfect example of that is Erin Lindsay and Kelly Severide, from “Chicago P.D.”

Christian Stolte, Taylor Kinney and Sophia Bush

and “Chicago Fire” respectively.

And for that, we thank them.

Severide, in particular had some serious romantic success outside of the “Chicago Fire” cast.

He also spent time with “Chicago Med’s” April Sexton and Anna Turner, perTV Guide.

As far as characterization through relationships goes, these two really shine.

desk sergeant Trudy Platt.

The couple are the only characters from separate shows to find lasting love, perUs.

Mouch and Platt continuously bring out the best in one another and fans love to see it.

While every viewer likely has their own ‘ships, these ones are pretty good as far as crossovers go.