just binged season 4

I agree, hownos.

I was wary about watching it at first, because I thought it would just be a tag-on for a story that was essentially already finished, but had been dragged up again to justify making (and selling!) a new series. And I was wrong. It wasn't gratuitous at all.

I think some of the stuff DCI Huntley said (no spoilers!) was intentionally setting up series 5. There's clearly still more to be resolved.