Nick Burkhardt thought he prepared himself for the realities of working as a homicide detective until he started seeing things he couldn't explain. Nick's life turns upside down when his Aunt Marie reveals they are descendants of an elite group of hunters, known as "Grimms," who fight to keep humanity safe from supernatural creatures. As Nick digs deeper into her past, he realizes that he will have to shoulder the responsibility of his ancestors.
Nick is forced into hiding after Captain Renard pins multiple Black Claw deaths on him, making him a wanted man.
Hank and Wu find a solution to stop Renard while Nick is still on the run. Adalind receives a phone call that throws her into the middle of everything. Back at the spice shop, Monroe and Rosalee's adventure in babysitting takes an interesting turn when Diana demonstrates her power. Meanwhile, Eve and Trubel work to solve the mystery of the cloth found with the healing stick.
In order to stop the rise of Capt. Renard, Nick devises a plan that will take him out of his element. Adalind and Monroe do everything in their power to keep the plan on track. Meanwhile, Eve and Rosalee race against time to get the spell ready before it is too late.
Nick, Hank and Wu investigate a terrifying new Wesen who terrorizes a young family and has a surprising motive. Capt. Renard is reeling after an unexpected guest appears. Meanwhile, Diana has some interesting news for Monroe and Rosalee. Elsewhere, Eve returns to the catacombs beneath Nick’s loft to search for answers to her bizarre visions and side effects from being healed by the mysterious stick.
Nick and Hank join Wu to investigate a bizarre murder in a local park. Elsewhere, Capt. Renard continues to deal with a ghost from his past. Meanwhile, Monroe and Rosalee visit the doctor to see if Diana's premonition is true. Back at the loft, Adalind finds a very weak Eve in the tunnels and mysterious drawings scrawled on the walls.
Nick, Hank and Wu investigate a local hotel after a grisly murder leads to one of its guests who claims to be haunted by a frightening creature in the night. At the Spice Shop, Monroe, Rosalee and Eve continue to research the origins of the symbols on the cloth and may be getting closer to unlocking its mystery. Meanwhile, Capt. Renard continues to be haunted by his past transgressions.
Rosalee surprises Monroe with a getaway for his birthday and invites most of the gang to join them. Things take a shocking turn when a hotel employee targets Nick in an effort to avenge his father. Meanwhile, Eve gets a visit from a dark force that she has seen before. Elsewhere, Capt. Renard spends the weekend with Diana when a former ally decides to get even.
Deadly attacks on a team of scientists lead Nick, Hank and Wu on a investigation unlike any they have had before. Meanwhile, as the research continues into the origins of the cloth, Monroe and Rosalee learn that Eve is still feeling the after effects of the death grip. Elsewhere, Capt. Renard reaches out to an old friend to get answers to the origins of the symbols drawn by Diana.
Nick, Hank and Wu are called to the scene of the crime where a man claims his friend was consumed by a tree-like figure. Meanwhile, after the gang learns of Eve's disturbing mirror encounter, everyone takes extra precautions. Elsewhere, Capt. Renard searches for answers to what Diana was drawing.
After a series of brutal and deadly attacks, Nick and Hank find an unlikely lead in a local nursing home. Meanwhile, Eve goes to Adalind to get answers that only a Hexenbiest can provide. Elsewhere, Capt. Renard confronts Nick about the mysterious symbols and tries to strike a deal.
Eve goes on a mission to take on the mysterious force she saw in the mirror and finds herself in unfamiliar territory. When the gang discovers what she has done, Nick finds a way to join her. Meanwhile, an uneasy alliance is established when Capt. Renard is brought in to help and discovers this all may be connected to the person he cares for the most, Diana.
The prophecy that was uncovered comes to pass when a dark force arrives in Portland with its eyes set on Diana. In an effort to protect her, Nick, along with Capt. Renard and Adalind, returns to the scene of his first investigation as a Grimm. Back at the Spice Shop, Monroe, Eve and Rosalee make a discovery that uncovers the origins of the mysterious stick. Meanwhile, Hank and Wu are called to a crime scene that is connected to the gang's greatest threat.
In the series finale, Nick faces off against his greatest foe yet as it seems no weapon can defeat him. At the Spice Shop, Monroe, Rosalee and Eve search for answers and stumble upon a rare potion that may help the fight. Elsewhere, Capt. Renard and Adalind try to keep Diana and baby Kelly safe as the threat has its eyes set on the children.