Doctor Who Christmas Special: What to expect from The Husbands of River Song

The Doctor Who 2015 Christmas Special is but 20 days away! So collected here for your delectation and consideration are some points to look out for and think about before The Husbands of River Song airs on Dec 25. Warning - some mild spoilers ahead.

• There is one story writer Steven Moffat has always wanted to tell - this is that story. The River story is being "paid off" - though it's not necessarily the last time we will ever see her. If it was her last, it would be "perfect".

• River is married to King Hydroflax and carries a Sonic Trowel.

• River is in the middle of her own adventure which the Doctor stumbles into it and causes her very carefully worked-out plan to go slightly wrong. She’s on a mission to retrieve a very famous diamond and she is trying to get it from the clutches of King Hyrdoflax.

• Matt Lucas plays a character called Nardole and he is pretty much River’s henchman, he’s helping her out on this adventure. Due to a misunderstanding on Nardole’s part, the Doctor gets thrust into River's plan.

• As far as River is concerned, The Twelfth Doctor’s face (Peter Capaldi) is not possible, it’s an anomaly. As far as she's concerned there are rules - The Doctor only has a certain amount of faces.

GUIDE TO THE 2015 DOCTOR WHO XMAS SPECIAL

• The Doctor gets to see the "true" River because she can be her absolute self and behave how she likes as she thinks he isn't there.

• The Doctor becomes River’s companion. There's a scene where he does the "Look, the TARDIS is bigger on the inside!" schtick, pretending it's the first time he's seen it.

• Lots of aliens in this ep due to different locations visited in space and time.

• The "Trap Street" from Face The Raven returns, though it is redressed as Christmas street from another planet, possibly Mendorax Dellora - a snowy colony world.

• And apparently, Jim the Fish fans will be pleased....