: Polly mentions a specific location she needs to visit, which becomes the primary clue leading the team to a breakthrough in the case.
: Dr. Daniel Charles is brought in to help Lindsay and Halstead connect with Polly, who is disoriented and heavily traumatized. [S3E22] She's Got Us
: Antonio and Olinsky investigate Horizons , a pyramid scheme/self-help group that the victims were involved with, looking for potential suspects. : Polly mentions a specific location she needs
While there isn't a specific "gadget" or "app" highlighted, the episode focuses on the following crucial investigative elements: [S3E22] She's Got Us