Most suspense novels built around gambling take you down the dingiest back alleys to mayhem or death on a barroom floor. No stereotypes here. Barney runs the biggest crap game in New York, but he's a P.T.A.-perfect gentleman. Mr. Martin owes him $100,000 and Martin works in a beautiful bank where some bonds are to be Converted. Enter Captain Jose Maria Carvalho Santos Da Silva, a handsome Brazilian bloodhound. Double cross, triply confounded.