Readers may be confused about whether Ellis, who has sold more than a million romance novels under the name Leanna Wilson, is creating a sci-fi thriller, a mother-daughter drama, or a love story. Ellis weaves an engaging tale that finally settles down into a love story with a bit of conspiracy theory thrown in. Bryn Seymour was nine when her mother died on the same day Apollo 11 landed on the moon. Forty years later, she stumbles across new information and heads to Texas to track down a man who knew her mom. Was she involved in NASA spying? Are Howard Walters’s suspicions about NASA coverups true? What does he know about her mom’s death? And what about sparks that fly between Bryn and Howard’s son, Sam? Readers will appreciate Ellis’s humor and witty dialogue, and some will relish remembering the Apollo years as she slowly reveals the details of Jennifer Seymour’s death and Bryn’s healing from it. Ellis bounces through this novel with periods of levity and seriousness, fluency and stuttering. (Mar.)