Once a Spy by Keith Thomson

Drummond Clark is an old man with early stage Alzheimer's. But Drummond hasn't lost any of his edge as his son Charlie is about to learn, daddy's a retired super spy, a national hero and a fly in the ointment of his protégé’s arms dealing business. When Drummond's apartment is blown up the pair are forced to go on the run and Charlie gets scattered glimpses of his real father, while evading some of Dad's old friends. Thomson delivers a funny, suspenseful, thrill ride that you'll have trouble putting down.