Last Survivor

A priceless plant, a rare African cycad thought to be extinct and prized by collectors, has been discovered, then stolen. Joanne Flack, widowed and broke, is the prime suspect for the crime. While supposedly hiding out in London she single-handedly foils a terrorist plot, killing a lone-wolf gunman.
The former mercenary turned CIA contractor, Sonja Kurtz, uncovers a link between the missing plant and the terrorist who tried to kill Joanne. The US Government thinks that if it can find the missing cycad it can foil an attack to rival 9-11.

Hot on Joanne's trail is retired US Fish and Wildlife Department special agent, Rod Cavanagh who knows his plants and knows his target - he's her former lover.

Joanne is a member of the Pretoria Cycad and Firearms Appreciation Society. She, Sonja, and Rod enlist the help of this group of aging gardeners and gun nuts to find a plant worth a fortune and the traitor in their midst who is willing to kill for it.