SVU and Chicago PD officer Erin Lindsay try to track down Lindsay's half-brother, who may be able to help take down a child pornography ring.

The crossover starts on Chicago Fire S03E07 Nobody Touches Anything (I). It continues on Chicago P.D. S02E07 They'll Have to Go Through Me (III).

A woman is followed home and raped outside her building, where several neighbors witness the crime but fail to call for help.