Disco's Secret Stash

Requirements- CL 1
Creates a small box that is completely invisible and intangible to all but the spellcaster. Can hold up to 5 by 5 ft per CL. Once the spell has been cast, the box may not be moved. The box is COMPLETELY undetectable (seriously, nothing can find it, even magic), and can not be dispelled.
If the Caster dies, the box becomes detectable and tangible (but not visible). Passing a DC 15 Summon Magic check allows creatures to detect the presence of a box created by the dead caster of a Disco's Box spell.
If the caster of Disco's Secret Stash is able to use the spell Greater Teleport, they are able to access the box from anywhere using Greater Teleport (even outside the spell's range without metamagic).