He asked me today, how, in one of the last episodes of the most recent series, Captain Jack travelled with the TARDIS clinging on to the outside. I said, 'Well, he can't be killed because of the Rose looking into the time vortex...blardy blardy blah'. He rolled his eyes at me and said 'I know all that I mean how come the TARDIS didn't just disappear around him like it does to other people?' I was stumped. Can anyone enlighten us?