SVU joins Chicago P.D. in a manhunt for two notorious escaped serial killers.

The crossover starts on Law & Order: Special Victims Unit S17E14 Nationwide Manhunt (I).

Responding to a call about a suspicious duffel bag at the Chicago Lakefront, Voight is horrified to discover that the bag contains the frigid and unmoving body of a newborn baby. Meanwhile, Voight is surprised to hear that his son is in town and Burgess and Roman grow closer.

Voight calls the team to investigate a homicide involving the only witness in a rape and murder case against an extremely young man, Oliver Tuxhor. Intelligence looks into Tuxhorn's family and their finances as they try to determine if someone was paid to take out the victim. Meanwhile, Stone offers Antonio a job as lead investigator for the state attorney's office, and Burgess and Sorensen's body cameras capture a bizarre exchange with a man that they pull over.

When a charred body is found in a torched house, Intelligence must work to identify the victim, as well as a young boy who is found badly injured inside. As they look to determine the cause and who may have been involved, they are faced with a web of secrets and lies. Meanwhile, Lindsay and Halstead receive an odd warning about Rixton that leaves them suspicious.