Engagement Between Enemies by Kathie Denosky

Finding out that he was a tycoon's secret grandson shocked Caleb Walker, especially when he was made president of his family's financial consulting company. Yet his biggest surprise was Alyssa Merrick. Threatened by the new boss, the spitfire constantly fought his innovative ideas. But after a scandalous rumor erupted, honorable Caleb made Alyssa a proposal she couldn't refuse....