The gardens of Ranleigh are delightful in the summer—just the place to fall in love, or fall over a dead body. When Lady Althea accompanies her sister–in–law, Jane, to a house party at Ranleigh, she hopes it will be a welcome return to peace and tranquility. Long walks and lazy days are the things Althea needs to advance her scientific studies and to decide whether or not to give up her freedom and marry the handsome and enigmatic Duke of Norwich. However, when she finds the body of a guest in the ornamental pond, she is thrown into yet another mystery. In her search for the truth, she must unmask Napoleonic spies, dig up long buried secrets, and forge new breakthroughs in forensic science. As puzzling as the case is for the brilliant lady detective, Norwich's sudden disappearance is even more confounding. Has he changed his mind about marrying her? Althea must come to terms with the fact that love is the most perplexing mystery of all.