User blog comment:MasterCharmander13/DWA Season 5 Finale Part 1 Hints and Teasers/@comment-27270572-20151031130104

1) This must be a Tetra line! Definitely Tetra like.

2) A big number meaning absolutely nothing until I read the story.

3) A way of climbing, I hope it is for that context anyway.

4) They see some sort of battlefield which will be a part of the finale, perhaps a huge battle will occur.

5) Something has been backed up, River Song return confirmed?

6) Two personel are climbing it now.

7) The intitals of the title?

8) How far the arc has gone back to, Rassilon return confirmed?

9) Acirg? Kumfd? Dmfzx? I have not a clue :P.

This is shaping up to be one huge finale and my predictions are that the Doctor will regenerate, Shalek will leave and Tetra will remain for the next Doctor. But that is for the whole finale not just this first part.