At one point, West asks Cassidy about a sex worker he and Cragen were both involved with, referring to Carissa Gibson and the events of Rhodium Nights (2012), Lost Reputation (2012), and Above Suspicion (2012).
Benson moves into a new apartment with Cassidy after her previous apartment is trashed from her kidnapping by William Lewis.
This episode implies that Ed Tucker and Amanda Rollins are on unfriendly terms after he investigated her in his last appearance, Deadly Ambition (2013)