Natalie was excited about her mission: using her map-reading skills, she was planning to get us from the north end of Kensington Garden to the Imperial War Museum. We would be crossing three parks and the River Thames. We decided we would walk through the parks and then take a taxi. Within an hour, with Natalie guiding us to the end of Green Park where we caught a taxi, we were dropped off by one of London’s excellent cabbies at the front gates of the Imperial War Museum, which stands in the middle of a park. It’s building was formerly the central portion of Bethlem Royal Hospital, or “Bedlam,” which…