If you’re searching for a plot, or characters, or just a bit of inspiration, can I suggest old newspapers?
My local library (and probably yours too) has a computer archive of all sorts of old newspapers, including The Times going back centuries. I’ve often used them for research purposes. But what I have found is that although I start just searching for one or two things, I get sidetracked. Last time I got caught up in a fascinating court case and ended up reading all the reports. I find myself reading accounts of murders and frauds and disappearances. I read the actual words of people who died a hundred years ago, but their anger and fear and passion are still there, right on the page.
I’ve found some real life affairs I can adapt for the next book. I also found some real life people doing acts I thought I’d have to invent people to do. Not only have I discovered quite a lot I didn’t know about Victorian London, I’ve been given some brilliant ideas.
And the best thing about trawling old newspapers for ideas is that it’s all true. If someone says to you ‘that’s ridiculous, that couldn’t happen’ or ‘that character is unbelievable’ you can say ‘ah ha, but it is true!’. It’s amazing what really happens, and ends up in the newspaper.