At a contested review hearing, father’s counsel requested to cross-examine the social worker, and present father’s testimony and other evidence on the issue of whether reasonable services were provided. The court denied father a contested hearing, and required counsel to make an offer of proof to determine if the entire line of cross-examination was relevant. The court refused to hear evidence offered by father. Father filed a petition for writ of mandate, which was granted by the appellate court. At review hearings, the Department bears the burden of proof. While reunification is ongoing, due process requires the court to permit a parent to have a contested hearing without conditioning that right on a demand for an offer of proof. The trial court was ordered to consider all relevant evidence at an 18-month review hearing, including any new information.