Doctor Who: 12 Cool Details Russell T Davies Just Revealed About New Earth & Gridlock
6. Budget Constraints Held Back Davies' Vision For The Gridlock Undercity
As the name implies, Gridlock's Undercity is entirely underground, sealed off from the rest of New New York above the surface. But if it's underground, why is there rain?
Well, we don't really know (although "because Doctor Who" is a pretty solid explanation), but in a tweet, Davies hinted that it's because of the Undercity's great height: its roof is so high that it ended up developing its own little atmosphere.
Furthermore, if Davies' full vision had been put on the screen, we'd have actually seen this roof for ourselves. The writer wanted to show a "metal sky" high above, "so high it's got clouds and rain". Unfortunately though, budget limitations - Doctor Who's most potent adversary - prevented this from happening.