The Light Between Oceans by M.L. Stedman
It is 1926 on an isolated island off the coast of Australia. As lighthouse keeper Tom Sherbourne and his wife Isabel yearn for a baby, something unimaginable comes crashing in on their world. This story of isolation, love, loss, and the morality of telling the truth has been made into a movie starring Michael Fassbender, Alicia Vikander, and Rachel Weisz.