To get ahead she'll have to become a man -- and a man, she always thought, never lets love get in the way. Clementine dreams of being a naturalist -- a career that leaves no time for romance. To sneak on an adventurous prospecting expedition, Clementine will have to convince everyone she's a man. A mysterious tonic offers her just that disguise. But "Calvin," as she calls herself now, had no idea what she was giving up. When Wesley, the expedition's gentle preacher, catches her eye, she can't get him out of her head; not his lush lips, wide brown eyes . or broad chest. Dare she reveal her secret to him, and can she keep her career if she does? Among run-ins with cowboys, natural disasters, and traveling shows, Wesley's most fascinating adventure is meeting Calvin.

Though Wesley's betrothed, the cute, clever naturalist threatens to make him fall into temptation.