Bgztl (depending on the incarnation) either exists in or is connected with the extra-dimensional space known as the Phantom Zone.
Producing only a brief and low amplitude shockwave, the squadron disappeared into extra-dimensional space and picked up speed.
Mention of Heim's physical and theological concept of extra-dimensional space can be found in a 2001 puzzle book by the popular mathematics writer Martin Gardner.
The 7 Door leads to an extra-dimensional space that exists in neither of the worlds nor the Void.
He can store items in sub-space "closets", pockets of extra-dimensional space which can hold items as large as a human being until Elric needs them.
Berg'inyon leaped out and grabbed the woman, tugging her hard into the extra-dimensional space, and Kimmuriel shut the door.
This city is not literally shrunken, but exists in an extra-dimensional space, occasionally connected to the Phantom Zone.
The costume exists in an extra-dimensional space known as "Elsewhere" until summoned by voice command (the wearer would say the words "costume on!")
The evidence will consist of heavy particles known as Kaluza-Klein modes that travel in extra-dimensional space.
Other wondrous items can store items in extra-dimensional spaces, such as the bag of holding or portable hole.