Nick (David Giuntoli) is a detective in the Portland police department when he discovers that he is a Grimm – kind of a warrior who defeats evil creatures (wesen). Wesen are people who have a creature that they can turn into – and it is past encounters with these that have formed fairy tales – especially the Grimm Brothers from Germany. When he discovers this, it is during an encounter with Monroe (Silas Weir Mitchell), a clockmaker and vegetarian Blutbot (a kind of wolf creature). Nick has a strong moral compass and finds a different way to being Grimm – rather than killing all the wesen, he tries to find ways for everyone to co-exist. That’s the start, and with 6 seasons, there are conspiracies, romance, secret organisations, good characters turn bad, bad characters turn good – all kinds of stuff happens.
For me, the first few seasons were really the best. I love fairy tales retold in some way, and I love a police procedural – and this has both. However, I felt that the bigger story arcs started to take over – they became increasingly ridiculous, and I struggled getting through the end of the series.