Actors starring in a Broadway show adapted from a novel often pore intently over the original source. Many plow eagerly through the text multiple times, dog-ear the pages and load it with margin notes.

Then there is “Natasha, Pierre & The Great Comet of 1812,” currently in previews at the Imperial Theatre. Its source material? Leo Tolstoy’s “War and Peace.”

In preparation for their roles in the Broadway musical, many of the show’s principal cast members say they have read the complex 1869 epic. For some, who have been with the production through its off-Broadway development, it has taken years to finish.

Others haven’t exactly gotten all the way through the novel which, depending on the translation, can run upward of 1,000 pages.

The reading isn’t a cast requirement, per se, but actors say the text has proved helpful—and even cathartic—in preparation for their roles. Some say they have found redemption or moments of joy for their characters.