You touch the locket or similar object used in the casting of this spell. For the duration, it becomes holds a demiplane within it. While it is on your person, you can use your bonus action to enter the demiplane. In addition, when you are targeted by an attack, you can use your reaction to go into the demiplane, avoiding the attack.

When you enter the demiplane in either of these ways, the object you made hold the demiplane remains in the plane you were in when you entered the demiplane, falling to the ground unless something stops it from doing so. The object with the demiplane inside has 100 hp, resistance to all damage types except for force, poison, and psychic, and immunity to poison and psychic damage. While you are in the demiplane, reducing the object to 0 hp causes you to be expelled out of the demiplane and the spell to end. Reducing it to 0 hp while you are not in the demiplane ends the spell.

The demiplane is a small cube made of adamantine, just large toughen to fit you. If you change size while the spell is in effect, the demiplane changes in size to accommodate you. While in this demiplane, you can use your bonus action to leave and appear wherever the locket is.

After the spell ends, the object you used to hold the demiplane crumbles to dust.