Stephen Dobyns pulls off a neat misdirection in this brazenly titled comic crime novel. On its face, “Is Fat Bob Dead Yet?” is a frivolous romp through an underworld of solecism-spouting thieves and doltish enforcers. But for a book with a cigarette-smoking beagle on its cover, there’s surprising depth here, as Dobyns convenes an ensemble cast whose thwarted ambitions suffuse an antic storyline with an air of poignancy.