Alfi's Water Bubble

A 10-foot barrier of water materializes in a space near you for the duration. It could take the form of a singular wall covering a cage, a stationary bubble underneath a body of water's surface, or a dome above ground. The spell ends if you leave the area enclosed. 

Nine creatures of Medium size or smaller fit inside if in a bubble or dome shape. The spell fails if cast in such a form including more than nine creatures. Creatures can move in and out of the barrier by parting the water, and may cast out of the barrier in the same fashion. Ither creatures may not do so. Spells and magical effects cannot enter the vacinity of the barrier. The inside space of the barrier remains unchanged. 

Until the spell ends, the barrier remains liquid. You can, as an action, change the dome to be made of ice or snow. Doing so lowers the interior temperature of the barrier.