Charlie and Rex reveal a conspiracy within the parkour community, after a thrill-seeker falls to his death.

Sarah finds herself in the middle of a hostage situation at a medical testing lab. When the team realizes there's no way inside without aggravating the gunman, Charlies sends Rex in to monitor the situation.

On the third anniversary of Charlie and Rex's partnership, Charlie recounts how a high-stakes kidnapping brought the duo together on their first case.

When Rex is accused of attacking a decorated former police officer, Charlie enlists the help of an unorthodox ally to uncover the truth in the hopes of restoring Rex's position on the team.