The Doctor races to stop Thawn from destroying the Swampie settlement and then works to destroy Kroll once and for all.
Did You Know?
The Doctor, talking to himself before his final encounter with Kroll, says he is seven hundred sixty years old. This suggests he is either rounding up (as his age was given as seven hundred fifty-nine in "The Ribos Operation") or he's had a birthday since beginning the Key to Time mission. A birthday scene was originally planned for "The Stones of Blood" but dropped by Graham Williams
, who considered it "too self-indulgent". See more