`` stella , '' perry mason , with his dark-eyed innocence to protect the law , accelerated a whim like the tire of a packard over gravel , when the headlights go swimming among the shrubbery and the lurk of danger is like the plug of a .38 : `` that case , what was it , the one marlowe settled , '' look of puzzlement , `` over in san francisco , the porno ring , black mail ? ''