Kevin Whately has hinted that Lewis will end after Series 8.
The Inspector Morse spinoff returns to ITV for an eighth series this month, but the actor says it will likely be the last, per BBC News:
“Everything has a life span and I think it’s gone on long enough. There were 33 Inspector Morse stories and we’ve now done 30 Lewis.
I suppose it’s a sentimental thing but I wouldn’t want to do more Lewis than we did Morse because I do still think of it as an offshoot. It’s a long time to play one character, but sometimes it only feels like yesterday that we started.”