When a luxury yacht owned by a reputed South American drug trafficker mysteriously sinks and the Navy is suspect, Harm, Mac and Bud are put on the case. Meanwhile, Artemus Sullivan, a World War II Navy veteran, with the help of his aged cronies, devises plans from a nursing home to make sure the drug dealer responsible for Sullivan's grandson's death is brought to justice. But when Sullivan is kidnapped by the drug dealers, his mettle is tested, as is that of Harm and his team as they race to rescue the war hero.