It appears that a defendant (you or another defendant) filed an opposition to Plaintiff's voluntary dismissal as to an unknown party. There should have been no reason to file an opposition to this. In any event, a hearing has been set on that defendant's opposition. The judge will wonder why this was set for hearing as a Plaintiff has the discretion to voluntarily dismiss any or all defendants from a complaint. You should go to the hearing, especially as it seems it was you who filed the opposition. Be advised that the judge will not be able to give you any legal advice, but will simply explain the reason for her/his decision.
Mr. Vicary is licensed to practice law in Florida. The response herein is not legal advice and does not create an attorney/client relationship. The response is in the form of legal education and is intended to provide general information about the matter within the question. Oftentimes the question does not include significant and important facts and timelines that, if known, could significantly change the reply and make it unsuitable. Mr. Vicary strongly advises the questioner to confer with an attorney in your state in order to ensure proper advice is received.