Stop in Heathrow

We had 12 hours in London to tour around. We went to Waxy O'Connors which ended up being a very unique, full of character pub! The food, music and company was great! We walked up and down Thames River before taking the tube back to Heathrow. We had to switch tubes during the direct route, and the tube kept stopping and giving announcements stating where it was ending. Very confusing and stressful. Needless to say we obviously got to the plane in time!