You attempt to craft illusory walls around a target creature within range. The target must make an Intelligence saving throw. Upon passing, the target is unaffected. Upon failure, the target sees or otherwise senses a set of wooden walls springing up from the ground in a 20 foot cube around them and trapping them inside an illusory building with no perceivable exits.
An affected creature can use its action to examine the walls with an Intelligence (Investigation) check against your spell save DC. If the check succeeds, the creature realizes that the building is an illusion, and the spell ends. Witnessing another entity enter or leave the illusion grants the affected creature advantage on the investigation check.
While affected, a creature may not exit the illusion and can only perceive creatures within it.
* - (a bit of fleece)