I Married a Dead Man

I Married a Dead Man is a mystery novel by Cornell Woolrich. The entirety of the story is told in the prologue and first 7 chapters, so by the time I finished 51 chapters and a post script I felt like I had been completely filled in on all the details. But, still, how many details did I need if I'd known the story since the 7th chapter. Time.com has an article describing Woolrich's unusual life and style. The book seems to be out of print.

from the back of the book:

Pregnant, abandoned by her lover, and desperate, Helen boards a train heading west. She meets Patrice, a happy young expectant mother who's traveling with her husband, Hugh, to meet his family for the first time. Patrice lets Helen try on her wedding band - just before the train crashes, killing Patrice and Hugh. Thinking Helen is their widowed daughter-in-law, Hugh's family welcomes her into their rich and loving home. For the first time, Helen's life is good - until her ex-lover comes to town with blackmail on his mind.

This book has been adapted for film several times, and Senses of Cinema has this to say about the book:

The opening section of I Married a Dead Man is pure Woolrich, focusing on a “typical”, vulnerable, person trapped within a hostile universe with little hope of salvation. Although the specific nature of the “trap” varies from novel to novel, its function is always the same – to dramatise Woolrich's paranoid view of existence whereupon the individual is shown to be impotent and unable to understand, let alone control, his or her world.