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 pr...