Unusual deaths start to occur in a rural northern Ontario's doctor's practice. These appear to be "hot shots" -deliberate overdoses of narcotics. The bodies are each found near an erratic boulder, a huge rock moved by glaciers thousands of years ago. Dr. Barbara O'Rourke has a friend, a lawyer, Chloe Wexford, who helps when one of Dr. O'Rourke's patients is arrested for a possibly related death of her husband years earlier. Dave O'Reilly, an OPP officer who is also a friend of Dr. O'Rourke, may or may not be implicated in the erratic boulder deaths. There are also links to a fire in Ottawa decades earlier. Not unusual in small towns in the north, there are challenges bringing the perpetrators of the "hot shots" to justice. The murders take place near an erratic boulder moved by glaciers thousands of years ago and the path to justice takes a shaky, erratic road as well.