[s1e19] Compass -

After hearing that Frankie died in a lab fire, Mac travels to MIT with , who is on mandatory medical leave with a broken arm. Their investigative instincts kick in when they notice a suspicious man at the memorial and learn that Frankie's supervisor also recently died in a mysterious car crash.

: Mac creates an electric whip from a cut extension cord to defend the team against the gunmen pursuing Frankie. [S1E19] Compass

Mac eventually discovers that Frankie is alive; she to hide from someone trying to suppress her groundbreaking scientific research—identifying DNA from cold cases. The episode follows Mac and Jack as they navigate the tunnels beneath MIT to help Frankie finish her work while evading a killer. Key Story Beats & "Hacks" After hearing that Frankie died in a lab