Who was killing former drug addicts who completed treatment in rehab?
That's what the team tried to find out on Criminal Minds Season 14 Episode 9 when a professor from Lewis' past tipped off the BAU about an alarming number of overdose deaths.
With limited leads, the team turned to the treatment facility that everyone was linked to in order to find out whether a worker was playing god.
What they found out, however, threw them for a loop.
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Paul Dailly is the Associate Editor for TV Fanatic. Follow him on Twitter.