4 3 2 1 may be Paul Auster's greatest achievement, at 866 pages, it's certainly his longest book. It begins in 1947 in New Jersey with the birth of Archibald Isaac Ferguson. From that moment, Ferguson's life, and the book, take four separate, simultaneous and independent paths. Each chapter sets out a few years in each version of the characters life; after 4 versions, we return to the first for the next few years, and so on. It is a bit hard to follow, as each life shares some of the peripheral characters, but the events unfold differently. It's a masterpiece of control, deeply moving and deeply satisfying, as each version of Ferguson engages, to varying extents, with the events of the time.
It's not the first time this technique has been used by a writer or filmmaker, but I think this is the most accomplished iteration I've come across. You will need some time to spare, and some room in your brain, but 4 3 2 1 is an extraordinary piece of work, which will reward your patience.