A Civil Procedure Code, section 170.6 motion to disqualify a judge was not untimely because the current proceeding was based on a new petition independent of the original case. Commissioner Marpet was assigned to the original dependency case involving father’s children. After 10 months, Marpet terminated dependency jurisdiction and gave custody to mother. Within a month, another petition was filed alleging sexual abuse by father, and the case was assigned to the same Commissioner. Father filed a 170.6 challenge. Commissioner Marpet denied the motion as untimely because the case had originally been assigned to him 10 months earlier. Father filed a petition for writ of mandate. The appellate court granted the relief sought. The current dependency petition arose out of events which occurred after the conclusion of the original dependency case. This was a new case, not a supplemental petition in the pending case. When the challenge is filed within 10 days of the party’s appearance in a new proceeding, it is timely under section 170.6, subdivision (a)(2). Therefore the trial court erred in denying the peremptory challenge as untimely.