We see people using a driving application called ZoGo (similar to Uber). A man, Cade, is picked up by Sam who isn't talkative. Cade notices his ZoGo driver registered him as a no show and realizes he isn't Sam. He asks to be let out but the driver refuses to stop. He eventually drives into an alley and tasers Cade.
Sifter tells Mundo about their Boston case of a girl who was killed, Cade Matthews. A cell phone found at the scene of the killer was wiped as well as in his home. Krummitz helps Ryan and Mundo for their trip to Boston, leaving everyone else at the lab.
In Boston, a detective gives Sifter the killer's cell phone. He tells them that Cade was a cyber security expert, helped locate the Boston marathon bombers. Ryan finds out that Regina, his boss, and Cade we're in a relationship. They believe Cade's intelligence on classified information may have gotten him killed. He ended his relationship with Regina the night before his murder.
Mundo and Nelson find that Cade wiped his devices remotely from his cell phone. File recovery shoes the last thing Cade did was use ZoGo app, delete files and called 911.
Cade's autopsy revealed a die with the number 1 on it.
Cade's call to 911 was disguised as a pizza delivery but the operator did not get the hint, nor was she able to get a location. Krummitz reveals that Cade was apparently picked up by five different ZoGo drivers, so they have to try and figure out which one he got into.
Nelson finds that ZoGo was hacked. Mundo asks for the names of the drivers but finds out that they were independent contractors. Mundo managed to speak to all five drivers who did not pick him up. HE was in a ghost car, a man who hacked the app.
Cade was a first time ZoGo user. They believe he was chosen randomly and deleted his information because he thought he was chosen personally. They then realize that their target is a serial killer who uses the ZoGo app to find victims.
They ask the Boston detectives for missing person's files to compare the cases to Cade. They find a glitch in the ZoGo app at the same time Cade incident happened. The suspect uses the glitch as a window.
Krummitz appears flustered as he works on this case. Ramirez and Krummitz try to connect the cases with the glitch but are unlucky. They eliminate users who have posted to social media in the past few days as well as users who've used their cards recently and found Melissa Drake.
Melissa hasn't been reported missing because her family thought she was in another country. Melissa was picked up at the same time, 5:17 am, as Cade.
They manage to find Melissa's body and see that she too was strangled. The die in her mouth has the number 1 on it.
Nelson manages to track an email sent to all employees of ZoGo which spread malware on their system. Raven found an IP address which should lead them to their suspect.
Mundo goes to look for Patrick Murphy. He finds him at a taxi yard and tries to get away but fails.
They search his car for prints. Patrick claims he hired someone to send the email for him to piss off their employees. Ryan finds that he's telling the truth.
ZoGo's firewall had 15 attacks in two weeks but attacks stopped three days ago, the first glitch. Nelson believes the suspect infiltrated the system from the inside by either planting a USB drive, unknowingly inserted by an employee to find owner, or by disguising a router in the office to hack into files.
Mundo and Nelson go to ZoGo to check it out and find the router. Nelson manages to get the IP address.
The head to the address and find a shrine for a young by named Michael who was killed by a hit and run, a ZoGo driver who fled the country to avoid charges. They find the dice and see "3" is missing, fearing they're too late. The suspect may be Michael's father, Richard Davis.
Krummitz is court with Francine. She refuses to go in and leaves.
Raven uses GPS to find the car. Ryan send Mundo with SWAT. He gets to the car and finds a phone with the picture of a hand and the "3" die.
Krummitz testifies about his parents being shot 17 years ago. He also talks about losing his relationship with Francine, his sister.
Since losing access as a ZoGo driver, the team believes Davis is now registered as a ZoGo passenger.
Krummitz tries to find Davis. They narrow the search and find the car that picked him up. The team head there as soon as possible.
Davis has the driver throw out his cell phone and the team lose the signal. They track the Davis' cell phone instead. Ryan asks Sifter to control the traffic lights to slow Davis down. They turn all the lights green to cause some chaos. Davis is stuck in traffic so Ryan and Mundo go on foot.
Davis gets out of the car and makes a run for it. They shoot at each other but he is eventually caught. He tries to plead his case and Ryan tries to talk him out of hurting anyone. He drops his gun and is arrested.
The team meet in a bar and Ryan sees Krummitz upset. The man who killed his parents was released. The team support him and he realizes that they're his family.
image courtesy of Roger Wong/INFphoto.com