Final Paradox, the second in The Osgoode Trilogy.

Years back, George Pappas, a charming but ruthless thug, scammed the city’s elite of a huge sum of money. He promised to develop a drug to combat memory loss in the aged. No drug was ever made and the money was gone. Harry Jenkin’s client, Norma Dinnick, demands he find it. When she is lucid, she’s credible, but when she is mad, she just might be evil. This fraud upon a fraud is about to unravel.
Norma insists Harry sue Pappas for the money as well as Archie Brinks, a fast and lucky stock promoter. In court, Archie is shot dead with an old, ornately scrolled dueling pistol used as part of an intricate scheme to frame innocent parties with the murder. Someone else is after the money. But who?
Harry has to find the money but is his client mad or evil? Not an easy question to answer! And Harry’s father, who abandoned him as a child now asks his forgiveness after his botched suicide attempt. It’s a singular tale of murder, evil and fraud combined with the meaning of love and forgiveness.