Unusual ingredients found in their products are threatening the good reputation of Gardener's Spice & Herb Company, so R&P Labs agree to investigate. But what seems like a simple job takes a deadly twist when one member of the Gardener family has a fatal accident on an icy road and another is freeze-dried along with the herbs. Before long, the scientists turned detectives are separating a pair of battling brothers, babysitting a lively septuagenarian and finding themselves on very thin ice as they race against time to discover who is killing off their clients one by one.