In this video, you can watch an unknown liquid freeze and boil simultaneously. No, it's not magic. It's science!
What you're seeing here is a liquid reaching its "triple point"—the temperature and pressure at which the three phases of a substance (gas, liquid, and solid) co-exist in equilibrium. In this experiment, the scientists are changing the pressure in the beaker. When the liquid is at a certain temperature, it will do what you're seeing here.