The Litigators by John Grisham

The Litigators - David Zinc is a burned out attorney at the law firm, Rogan Rothberg.  When he quits, he spends the day in a bar and then walks into the struggling 2 man firm of Finley & Figg. Figg is always searching for the big case that will catapult them into the big time.  He believes he found it in the drug Krayoxx. While he is "paying his respects", so that the widow will hire them to probate her husband's will, the son of the deceased informs Figg that he believes that Krayoxx killed his father and that there is already a lawsuit against the pharmaceutical company.  Figg immediately jumps on the bandwagon, and files several lawsuits against the company, citing that Krayoxx killed the victims.  David, although he is wary of Figg's actions, joins the firm and assists Figg in plying the case.