There is never a dull moment in Bank of America’s attempt to resolve its Countrywide mortgage-backed securities liability. In a stunning move Friday, the law firm leading the fight against BofA’s proposed $8.5 billion settlement with Countrywide MBS noteholders removed the case from New York state supreme court to federal court. “The purpose of removal is to make sure that this proceeding is adjudicated in the proper forum,” Grais & Ellsworth wrote in a letter to lawyers for Bank of New York Mellon (the Countrywide MBS trustee) and for the big institutional investors who crafted the proposed settlement. “We believe in good faith that this proceeding is subject to federal jurisdiction as a mass action under the Class Action Fairness Act.” (Here’s the Grais & Ellsworth letter with the removal petition attached.)

The removal to federal court plunges the proposed settlement, at least temporarily, into more uncertainty than ever. Judge Barbara Kapnick, who is presiding over the unusual state court proceeding to evaluate the proposed deal, had imposed an August 30 deadline for Countrywide MBS investors to intervene in the case. She had also established a preliminary schedule for the discovery Grais & Ellsworth and other objectors’ counsel have demanded from BNY Mellon, BofA, and the institutional investors and their Gibbs & Bruns counsel. The removal to federal court means that Judge Kapnick isn’t in charge of the case, so it’s not clear whether lawyers are required to abide by her schedule.

The Grais & Ellsworth filing was a surprise tactic. The firm has been in the state court litigation since early July, filing its initial petition to intervene only days after Bank of New York Mellon, as Countrywide trustee, filed a suit asking for court approval of the settlement of investors’ claims. David Grais even appeared before Judge Kapnick at an August 5 hearing on objectors’ requests for expedited discovery. Grais & Ellsworth apparently waited to remove the case to federal court until Judge Kapnick granted the firm’s motion to intervene in the state court case on Monday. (Grais, who was not in the office Friday, didn’t respond to my e-mail; his partner Owen Cyrulnik, who signed the letter to opposing counsel, didn’t respond to an e-mail and phone message.)

You can bet that BNY Mellon and the institutional investors will move quickly to try to get the case back to Judge Kapnick, whose first substantive ruling, albeit on a minor procedural matter, went their way. Lawyers from Mayer Brown and Dechert (for BNY Mellon) and Gibbs & Bruns (for the investors backing the settlement) will be filing remand motions next week, possibly as soon as Monday or Tuesday. Whoever hears the remand fight — Grais & Ellsworth’s petition said the case is related to a Countrywide MBS investor suit before Manhattan federal judge William Pauley -- will have to deal with all kinds of novel questions. Among them: Grais & Ellsworth’s own previous precedent on put-back claims in federal court.

Grais’s argument for sending the $8.5 billion proposed settlement to federal court comes under the Class Action Fairness Act, the 2005 law that requires big-money class actions to be litigated under the oversight of a federal judge. CAFA also mandates that mass actions, in which at least 100 plaintiffs have filed parallel suits seeking money damages against the same defendant, be transferred to federal court. Grais & Ellsworth is asserting that because the proposed Countrywide MBS settlement will resolve the claims of investors in 530 trusts, it’s a mass action under CAFA.