What happened to Nicole?
That was addressed on Chicago PD Season 4 Episode 19 when Burgess was shocked to find that her sister had gone missing after a night out with friends.
Having flashbacks of what happened Nadia, Lindsay made sure the case was top priority for the precinct.
Things took a turn for the worse when there were reports of a body being found.
Was it Nicole?
Use the video above to watch Chicago PD online to get caught up with the latest developments on this hit NBC series.
Paul Dailly is the Associate Editor for TV Fanatic. Follow him on Twitter.