This spell shapes a creature's dreams. Choose a creature known to you on the same plane. Creatures that don't sleep (i.e. elves) can't be affected. You, or a willing creature you touch, enters a trance, acting as a messenger. While in a trance, the messenger is aware of their surroundings, but can't take actions/move.
If the target is asleep, the messenger appears in their dreams and can converse. The messenger can also shape the environment of the dream. The messenger can emerge from the trance any time, ending the spell. The target recalls the dream perfectly upon waking. If the target is awake when cast, the messenger knows it, and can either end the trance (and the spell) or wait for the target to fall asleep. The messenger can appear terrifying. If so, the messenger can deliver a message of no more than 10 words and then the target makes a Wis saving throw. If failed, a nightmare prevents the target from gaining any rest benefits. In addition, when the target wakes, it takes 3d6 psychic dmg. If you have a piece of the target's body (hair, nail, etc.), the target saves at disadvantage.
a handful of sand, a dab of ink, and a writing quill plucked from a sleeping bird