Mo. Rev. Stat. § 527.210
Any person who may claim an interest or estate in said lands adverse to that alleged in the said petition or petitions may appear and answer said petition, and resist the claims of said petitioner or petitioners in and to the said lands, and may also produce and submit such evidence and proof of his estate or interest in the said lands, as he, she or they, or any person acting in his, her or their behalf, may desire, conforming in all respects to the same rules of equity as herein provided for the government of petitioner or petitioners; and if, upon a final hearing of the petition, the court shall find the allegations of said petition to be substantially proved, it shall order a decree in said cause adjudging said petitioner or petitioners to be seized of an interest and estate in the said land, according to the allegations and prayer of the said petitioner or petitioners, which said decree shall be conclusive against all persons and parties who may appear and answer in said cause, or who shall have been personally served with notice, and shall be prima facie evidence against all other persons claiming said premises from the time of entering of the said decree.
§ 527.210, RSMo