When you run with the Doctor it songs like it will never end, but however hard you try, you can't run forever. Everybody knows that everybody dies, and nobody knows it like the Doctor. But I do think that all the skies of all the worlds might just turn dark if he ever, for one moment, accepted. Everybody knows that everybody dies, but not every day. Not today. Some days are special. Some days are so, so, blessed. Some days nobody dies at all. Now and then, once in a very long while, every day in a million days where the wind stands fair and the Doctor comes to call, everybody lives.River Song
The Thirteenth Doctor is the thirteenth incarnation of the Doctor.