Antonyms for the phrase "are on the scene" could include "are absent" or "are away." If someone is not on the scene, it means they are not present and cannot contribute to the situation at hand. Other antonyms could include "are unaware," indicating that someone is not informed about the situation, or "are uninvolved," suggesting that someone has nothing to do with the matter at hand. Additionally, antonyms could be related to the opposite action, such as "are departing," indicating that someone is leaving the scene, or "are disengaging," suggesting that someone is withdrawing from the situation. Overall, there are a multitude of antonyms for the phrase "are on the scene," each with their own unique context and implication.