Esteldir's Persistent Nictitation

Upon casting this spell, you immediately vanish from your current plane of existence and appear in the Ethereal Plane (the spell fails and the casting is wasted if you were already on that plane). On each of your subsequent turns for the rest of the spell's duration, as an action, you can switch again from the Prime Material to the Ethereal Plane or vice versa.

While on the Ethereal Plane, you can see and hear the plane you originated from, which is cast in shades of gray, and you can't see anything there more than 60 feet away. You can only affect and be affected by other creatures on the Ethereal Plane. Creatures that aren't there can't perceive you or interact with you, unless they have the ability to do so. Each foot of movement while on the Ethereal Plane costs one extra foot. 

At Higher Levels: When this spell is cast with a 6th level spell slot, the duration increases to 10 minutes; with a 7th level slot to 1 hour; with an 8th level slot to 8 hours; or with a 9th level slot to 24 hours.