D&D4 Wiki
Warding 28

You inscribe runes upon your foe, and it falls into a space beyond the normal bounds of the cosmos from which it might never return.

Time: 1 hour
Duration: Permanent
Component Cost: 170,000 gp, plus 5 healing surges
Market Price: 500,000 gp
Key Skill: Arcana (no check)

Imprisonment is a 28th-level ritual.[AP:156]

You imprison a creature within a demiplane created by this ritual. The creature to be imprisoned must be either helpless or willing, and it must be present for the entire performance of the ritual. When the ritual is complete, an invisible magical field envelops the creature, putting it into suspended animation, and the creature falls into a space beyond the normal bounds of the cosmos. Only divination rituals performed by creatures of your level or higher can determine the location of the imprisoned creature.

You must set one or more possible conditions that release the creature, should they come to pass. You can set an imprisoned creature free by performing a ritual of release that has no component cost and takes 1 hour. A freed creature has no memory of the events that occurred during its imprisonment, and it appears in the world on the ground closest to where it was imprisoned.