The spell imprisonment offers several different ways of taking a creature that fails its save 'off the board'. They remain imprisoned until the end of the spell, and then they are released.
Of the different types of imprisonment:
- 'Chaining' clearly binds the target to a specific place, so it stands to reason that at the end of the spell they would remain in that place but with the chains removed.
- 'Slumber' places the target into a sleep from which they can't be awoken. Presumably their body can be moved as normal, so that upon the end of the spell they would awaken wherever they were.
- 'Minimus containment' places the target inside a gemstone. The gemstone appears to be readily transportable, and at the end of the spell the target would presumably be released at the current location of the gem (and not necessarily at the location where they had been imprisoned or the current location of the caster).
These three seem straightforward and intuitive. It is the other two I am struggling with.
Burial says:
The target is entombed far beneath the earth in a sphere of magical force that is just large enough to contain the target. Nothing can pass through the sphere, nor can any creature teleport or use planar travel to get into or out of it.
Hedged Prison says:
The spell transports the target into a tiny demiplane that is warded against teleportation and planar travel. The demiplane can be a labyrinth, a cage, a tower, or any similar confined structure or area of your choice.
Neither of these two say where the target appears when it is released, unlike banishment, for example, which says "the target reappears in the space it left or in the nearest unoccupied space if that space is occupied."
With 'chaining' keeping the target in place, and 'minimus containment' apparently for transporting the target, it is unclear to me where the target of 'burial' or 'hedged prison' should appear:
- At their former location when they were imprisoned?
- At the current location of the caster?
- At either, at the caster's discretion?
- At the location of the creature who ended the spell, if that was not the caster?
Spells do what they say they do, but this spell says only that at the end of the spell the target is released, but not where it is released to.
Ideally I would like a RAW answer, but if there is none, I would be interested in RAI unofficial designer statements, previous edition versions of the spell, or general lore in the form of fiction, cards, etc..