Notes
1. We're building up to the big reveal of the 456 here. This is all about stringing out the tension as much as possible.
2. And remind the audience that this is an event which will have an impact outside the closed world of Floor 13.
3. Clem's history with the 456 was established in the first episode but this is his first sight of a nightmare which has haunted him almost all his life . Gwen's lack of reaction here is lovely. She's such a caring person normally but showing her so wrapped up in her own shock really gets the audience wondering what she can see. A very human moment.
4. I loved this moment of revelation. The idea that the 456 were fake took Captain Jack back to his roots in The Empty Child (never try to con a conman!) and was a twist the audience would never predict. Everyone was keen (except John Barrowman, he didn't get it, but but not growing up in Britain -he's Canadian or something- means he missed shows like Emu's Broadcasting Company and Emu's World and he doesn't have the same nostalgia for Rod Hull) but we hit problems pretty quickly.
Rod, of course, sadly died in 1999 and his presence here would have to be created using stand-ins, CGI, processed archive footage and a voice double. We would have been wasting money that could be better spent elsewhere. I still miss Rod Hull's presence though.
So in the next draft we ended up changing the 456 to real aliens. This had the advantage of strengthening other moments in the script such as Ianto's death. It becomes more meaningful both as a demonstration of the power of the 456 and emotionally for the characters and audience; rather than an awkward slapstick sequence with Ianto and Jack being chased around Floor 13 by a shrieking children's television presenter who attacks them with a fake alien on his arm, pretending to peck at them, until the pair fall out of a window. The aliens' motives are also clearer in the next draft, originally there were some problems with what Rod Hull wanted to do with 10% of the Earth's children; he planned to take them away to his Pink Windmill for reasons that never really become clear.
5. And we're off! A good way to avoid viewers dwelling on difficult moments in the plot is to show characters reacting as you imagine the audience might be at home.
Different: how the reveal of the true nature of the 456 might have looked.