Namgang Police Station's Traffic Crime Investigation Team cracks down on a second-hand car crime ring; insurance investigator Cha Yeon-ho who mistakenly gets arrested with the criminals, hands over a suspicious envelope to TCI leader Min So-hee.

The TCI members arrest an insurance fraud suspect, but must release him due to a lack of evidence.

TCI set out to capture the ghost responsible for the Ganghui Three-Way Junction's traffic accidents; Yeonho discovers that these collisions usually happen on rainy days as due to of poor roads.

The team investigate the case of a woman who jumped out of a moving car because the driver was allegedly sexually assaulting her; TCI takes on a hit-and-run case; a headquarters for the joint investigation unit gets established.

While investigating a hit-and-run case, TCI learns that it is tied to auto theft.

Yeonho gets audited due to the post on the police agency's website; Yeonho's claim of the car thief and the serial rapist being the same person gets refuted by the National Forensic Service's DNA analysis.