The case of the lucky loser

"Murder (where a corpse is dispatched twice) as Perry Mason gambles with his high professional standing in a game that's strictly table stakes, with a marked deck! The first lady in the case wouldn't even give her name. And the clear, youthful voice fluttered noticeably when Perry quoted his fee. On the other hand, the second lady unhesitatingly gave her name--and then some! But what did Dorla Balfour hope to get (in return) when she begged Mason to accept a thousand dollar retainer to handle a case that had already been tried and decided?"