A defendant may have affirmative relief against the plaintiff. Clark v. Clark, 62 N. H. 267, 268, 272; Cox v. Leviston, 63 N. H. 283, 287. Both parties are entitled to just and convenient procedure. Pearson v. Railroad, 63 N. H. 534; Boody v. Watson, 64 N. H. 162, 171-174, 178, 179. The defendants’ situation is such that justice and convenience require in this suit an adjustment of their conflicting claims in regard to contribution. It is not suggested that the plaintiff has any interest in their controversy. if they ask delay in the enforcement of his decree, the reasonableness of delay will be considered at the trial term, where an additional decree will be made when the question of contribution is tried.