Temporal Wall

You create a wall composed of the mist-smoke of the Demiplane of Time on a solid surface within range. You can make the wall up yo 60 feet long, 20 feet high, and 1 foot thick, or a ringed wall up to 20 feet in diameter, 20 feet high, and 1 foot thick. The wall is composed of translucent, shifting smoke and lasts for the duration of the spell. Anyone trying to pass through this wall in either direction suffer an effect like that of two cumulative slow spells. Creatures can make Wisdom saving throws to avoid each of these effects (one for each). Missiles, spell effects, and other ranged attacks are also slowed by the wall, causing physical projectiles to drop out harmlessly on the other side of the wall and granting advantage on saving throws against spells on the other side of the wall to the caster, or disadvantage on spell attack rolls made against targets on the other side of the wall.

Dispel magic cannot destroy this wall, though any magical item capable of destroying magic can affect this spell. Teleportation spell such as misty step and dimension door are unaffected by this spell and can allow someone to bypass the wall.