The end almost dropped this to three stars, but the overall is still a very strong and emotionally impacting story. There's some belabored dithering through the childhood of Maggie and Tom and sidetracks into the business doings of Tom as a young man that could have been much briefer in support of the narrative, but it could be that some of these details had an impact on my emotional connection to the characters. 
 It's almost as if Eliot really were writing for history, knowing that (of course) social mores change as generations progress - that a 21st century reader might need substantial background to understand how significant are the crimes of a young lady led briefly astray unchaperoned. 
 Setting aside the prolonged staging of the drama, Eliot is brilliant at developing human characters and providing natural and un-telegraphed plot complications. I do wish for a stronger resolution, but that is life, I guess, and that is what Eliot writes.