Dead Reckoning: an Al Pennyback mystery

Al Pennyback is just your run of the mill private investigator. He and Heather Bunche, his partner, are on retainer for a law firm, doing routine legal investigations. They handle the occasional over the transom case, so they're accustomed to strange cases, but when a morbidly obese client offers Al one hundred thousand dollars to pick up a painting worth three quarters of a million dollars, he learns what strange really means.
What he figured would be a well-compensated, but routine, and probably boring, pickup and delivery turns into a run for his life as rogue Russian gangsters decide he needs to die.