It seems your message got cut off—did you mean (2013), Matt Smith’s final episode as the Eleventh Doctor?
If so, here’s a concise review of that Christmas Special: Doctor Who 2005 2013 Christmas Special The Time...
Written by Steven Moffat, this episode serves as both a Christmas special and a regeneration story, sending off Matt Smith’s Eleventh Doctor after four years. It directly resolves the "Silence Will Fall" / "Doctor Who?" arc introduced in 2011’s "The Impossible Astronaut," and brings back Clara (Jenna Coleman) as the companion. It seems your message got cut off—did you
The Doctor is summoned to the planet Trenzalore, where a mysterious signal—later revealed to be a question asking his real name—emanates from a crack in time. The answer would either unleash the Time Lords (trapped in a pocket universe) or restart the Time War. The Doctor stays to protect the town of Christmas for hundreds of years, aging drastically, until the Time Lords grant him a new regeneration cycle. The Doctor is summoned to the planet Trenzalore,