I'm sort of worried about which train ticket to buy. I arrive in London from Houston at 7 AM sharp, allegedly. Is it going to be just an hour on the Tube to get to King's Cross? I want to have a bit of walkaround time in London to see the few sights that I can and then go to Kings Cross to catch my train. Hmmm.....might as well just take the plunge and hope for the best.