§ 872.610.Generally

This section states a basic but important point about scope: the trial isn't limited to testing the defendants' interests against the plaintiff's claims. Anyone's interest in the property -- plaintiff's included -- can be put in issue, tried, and determined in the same proceeding.

That matters because a partition action often surfaces genuine disputes about the plaintiff's own share, not just the defendants'. Rather than requiring separate litigation to settle those disputes, this section confirms the trial court can resolve all of it together, setting up the more detailed work that follows in § 872.620 (ascertaining title) and § 872.630 (determining lien priority).