Thirteen tax lawyers who worked until February at Fidal, France’s largest law firm, have turned their backs on the legal arm of Big Four firm KPMG to return to their former home, according to a person close to the matter.

Behind the about-face is an ongoing legal tussle between the two organizations that stems from the original mass departure, when 144 lawyers, including 26 partners, left Fidal early this year to join KPMG. The returning team—which includes four VAT specialists, five corporate income tax lawyers, and four with transfer pricing expertise— were part of that mass exodus.