As "Doctor Who" says goodbye to Peter Capaldi as the Twelfth Doctor, Jessica and Phillip look at some of the Time Lord's past regenerations. They discuss how 9 (Christopher Eccleston) became 10 (David Tennant) in "The Parting of the Ways," 10's change into 11 (Matt Smith) in "The End of Time, Part Two," and 11's regeneration into 12 in "The Time of the Doctor." They also talk about the Tenth's Doctor's "meta-crisis" regeneration and the War Doctor (John Hurt). Jessica and Phillip explore the mythos of regeneration - what's stayed the same and what's changed.
In their look into the TARDIS library moment, they examine the Fourth Doctor's harrowing journey in "The Deadly Assassin," the serial that first establishes the limit on the Doctor's regeneration cycle and also features the franchise's villain, The Master, attempting to extend his regeneraiton cycle.
How do you think "regenerations" have changed during "Doctor Who" and which is your favorite?