When Dead Detective Seamus is asked to investigate the death of wealthy businessman William Dunbar, he agrees, but there is an additional request. Will he take a detective-in-training along? Reluctantly, Seamus agrees and meets Mildred, who seems charming if a little headstrong. Suspects include Dunbar's family and staff, notably his beloved grandson Bud, who was with him when he fell from a bluff overlooking Lake Michigan. There's chemistry between Bud and a member of the household staff, Scarlet. Seamus wonders why they work so hard to keep it hidden. As they try to learn what happened, Mildred decides she must help Dunbar's adopted granddaughter Brodie, a problem child devastated by "Gramps" death. Brodie feels that no one on earth cares about her now, and Mildred becomes determined to convince her otherwise.
Disgusted by the fact that Mildred ignores the rules of non-interference with the Living, Seamus works on without her. Events soon spin out of control. A kidnapping leads to a desperate chase toward the Straits of Mackinac, where several characters find themselves in peril. Will Mildred become a lost soul? Will Brodie find the will to survive? Can Seamus help his host defeat the killer, or is he more hindrance than help? Nothing is sure except the reason behind it all. Just like William Dunbar, others he cares for might end up Dead for the Money.