S1 • E1
After spending years in the Peruvian jungle during his tour in Army Special Forces, Cascade PD Detective James Ellison developed hyperactive senses, which came back to him five years after his return to the US. He can see people in darkened windows at night from two hundred yards, hear the music playing on the radio of the car he's chasing after he's lost sight of it, and can distinguish between wood and plastic after both have been in a three thousand degree fire. Blair Sandburg, a local anthropology student, tells Ellison that he is a "Sentinel," who in ancient tribes would protect the village and seek out game using such hyperactive senses. Sandburg becomes Ellison's back-watcher and teacher of how to use his new powers as Ellison brings a whole new edge to the war on crime in Cascade, Washington.
S1 • E2
Jim tries to find a way for Sandburg to help him on duty. They need to talk to the Captain, but a terrorist manages to take control of Police Headquarters. Sandburg is one of the hostages. Ellison and Captain Banks try to figure a way to free all the hostages and take out the terrorists.
S1 • E3
When undercover police officer Danny Choi is killed at the hands of Tommy Juno, Jim must use his senses and his skills as a detective to prove Juno's guilt. However, Juno seems capable of being two places at once.
S1 • E4
The drug lab next door to Sandburg's apartment blows up leaving Blair homeless and getting Ellison involved in a local drug war. Blair moves in with Jim. Ellison teams with a former gang banger cop to try and stop an escalating drug war.
S1 • E5
A serial killer drowns his victims, ties a yellow scarf around their necks, leaves them in a warm bath and assumes their identities. His next target is Blair Sandburg.
S1 • E6
Cold medication messes with Ellison's senses while Jim and Blair try to defend a state protected witness and his female lawyer from attacks on a train.
S1 • E7
Rogue CIA agent Lee Bracket steals Ebola virus and uses it as a threat to force Ellison and Sandburg to aid him in stealing a prototype aircraft.
S1 • E8
Blair woos the daughter of a suspected arms dealer in order to help Jim bring down the father and stop the escalating violence caused by the influx of powerful weapons. Jim has to deal with a female ATF agent with an abrasive personality.
S1 • E9
Ellison's investigation of a series of diamond robberies is disrupted when Jim meets an attractive woman and is powerfully affected by pheromones. Sandburg connects this to Jim's odd reaction to evidence at the crime scenes.
S1 • E10
Sandburg takes Ellison to a monastery for what he hopes is a relaxing vacation. Jim isn't enthusiastic about this idea. One of the monks is murdered and the two visitors are the prime suspects.
Jim Ellison
Blair Sandburg
Simon Banks
Joel Taggert
Detective Rafe
Serena Chang
Carolyn Plummer
Megan Connor
Detective Brown
Rhonda