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.
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.
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.
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.
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.
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.
