In a securities case, the plaintiff sought to compel documents regarding a merger between EdgeMark Financial Corporation and Old Kent Financial Corporation. EdgeMark retained David Olson of Donaldson, Lufkin & Jenrette (DLJ) to act as its investment banker in connection with the merger. EdgeMark sent a number of documents to Olson that it claims are protected by the attorney–client privilege. The plaintiff argues that these documents are no longer protected by the privilege because disclosure to Olson resulted in waiver of the privilege. EdgeMark argues that after the plaintiff’s counsel threatened to sue it, EdgeMark’s and DLJ’s interests became “inextricably linked” because the litigation jeopardized the merger. As a result, EdgeMark argues, the documents are protected under the “common interest” rule, which is an exception to the general rule under the attorney–client privilege that the privilege is waived when a document is disclosed to a third party. The common interest rule protects from disclosure communications between one party and an attorney for another party where the parties are engaged in a joint defense effort. DLJ is not a party to the lawsuit and has not been asked to assist in the defense. Has the attorney–client privilege been waived, or does the common interest rule preserve the privilege?