Doctor Who Was Never About Showing Mercy

The latest hero of the time-travel adventure series Doctor Who, David Tennant, claims at one point that he "used to have so much mercy." Which started us wondering: When was that exactly? When he condemned his former best friend to a fiery death while the friend (the Master) begged to be saved? Or was it when he… » 6/19/08 5:00pm 6/19/08 5:00pm