Stephen goes back through ancient history so Karl can share his take on the medicine of the ancient world-from King Tut dying of a knee injury, to the Romans' commitment to hygiene, all the way through to the small pox virus. He thinks keeping a bit of the virus intact is like when the bad guy leaves James Bond alive for no good reason. Karl envisions a machine that lets your doctor experience exactly what their patients are feeling, since "you don't know if you feel well, because you've never felt being anyone else." Karl defends himself from Ricky and Stephen's doubts, quoting Einstein's famous words, "If an idea isn't daft, it isn't worth thinking about."
