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?
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Paul Dailly is a staff writer for TV Fanatic. Follow him on Twitter.