Against doctor’s orders, Ron “Pigpen” McKernan hit the road one more time with the Grateful Dead. The band’s 1972 tour of Europe is legendary. But at the time, Pigpen was just trying to stay above ground. You could hear it in his voice when he took the mic onstage. Close your eyes and his voice was a window into the past. But listen closer, and you’d hear something else. Something you couldn’t quite put your finger on. A distance. Some pain. Truth was, Pigpen was on borrowed time.