Maggie MacLaren longs to leave her hometown, even if she must quell her attraction to rugged steelworker Jake O'Neill. He is handsome and solid, like the ordinary life all around her. When refined Andrew Adair walks into Maggie's library, he sweeps her into his world of wealth and power, where at last her dreams seem possible. However, Andrew's world is not all it appears to be.
High above town, reclusive young widow Allison Kimball arrives at her family's exclusive mountain retreat to find tucked into her carpetbag a love letter. So begins a series of secret epistles and midnight trysts with a man who signs each note with a cryptic āDā. Their forbidden love story unfolds to reveal a truth that will threaten to tear them apart as their world comes crashing down in the Johnstown Flood of 1889.