Under-Universe
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The Fourteenth Doctor described that the Toymaker's domain as "a hollow beneath the Under-Universe", blaming himself for having "let the TARDIS fall" into this "other realm" in an earlier life. He also stated, in this realm, "science is a game" and that all who visited it were "toys". (TV: The Giggle [+]Loading...["The Giggle (TV story)"])
