A well written episode with some real tension and a clever assassin. The mythology is still vague.
7 Noble Houses each entrenched in the real world and vying for power within the Wesen world. Probably more Eurocentric or Old World, but with representatives spread globally. This says to me that Renard is in somewhat of a backwater, fairly far down the food chain, but he's ambitious and territorial...a big fish in a small pond and he'd like to change that.
The Varrek are like the Gestapo for the Noble Houses.
The Houses play power games that upset the rank and file Wesen. They are also similar to the Iluminati...secret masters of the world type folks.
There's a resistance. There's always a resistance
Grimms have allied themselves (in the past?) with the Noble Houses. Perhaps to keep the balance, perhaps for protection.
The Reapers are evidently a breed/faction of the Wesen that doesn't always obey the Royals. Grimms are their natural prey, but I imagine they are general badasses that aren't well regarded by the rank and file Wesen either. I guess next week we'll see more of that developed.
So, we're getting a picture and it looks pretty interesting. Lots of story fodder for the serialized long story arcs.