SJ was admiring the gray-haired man's stretching as he meditated in the Kendall Red Line stop. And then it hit him: Not only was the guy on the tracks, he was holding onto the third rail:

... The meditator was meandering down the tracks into the tunnel, bags in hand, not rushed but with intent. Now there were dozens of people, all watching him, many idly. I stayed on the phone, offering voice updates and a description for a third time. After a minute, something made him return to the end of the other platform and climb up. ...