(This article may contain spoilers.)

The 9th season of Doctor Who is almost over.This Saturday, BBC One will broadcast the last episode before the Christmas Special which willalso be the season finale, as usual.

And how has the season gone so far?The Doctor just lost his companion - Clara Oswald - and was trappedinside his own confession dial. After some struggle, he was finally able to escape and ended the episode - Heaven Sent - with some amazing new information, as we discovered that he was finally back in Gallifrey and as he confessed that he was the Hybrid we've been hearing about since the beginning of series 9.

Moreon thaton this Saturday episode - Hell Bent.

So let's focus on the Christmas Special and on what we know so far. We already have a poster, a clip and the episode synopsis and, as always, the whovians out there have been trying to find as much as they can about the series beforehand.

First things first. The iconic character of River Song will finally be back and will be face to face with the new Doctor incarnation for the first time. We were already expecting her, after all the episode was named "The Husbands of River Song" for a reason. But now, with the poster released, we can at last see her standing next to Peter Capaldi's Doctor.

After a long season of fans' anger about it, the poster also shows that the Doctor got his old sonic screwdriver back (he has been wearing sonic sunglasses).

River also has some sort of sonic device, which isn't altogether new. The poster also has them running from some sort of mechanical creature.

Now on to the synopsis. The Doctor comes to help a crashed spaceship and finds himself recruited into River Song's squad as they begin an exciting chase. From the brief summary we can also understand that River doesn't recognize The Doctor - Moffat already said that this episode takes place afterThe Angels Take Manhattan in her timeline - and that there are two guest stars.Man Down and Inbetweeners'Greg Davies and Little Britain's Matt Lucaswere casted in this Christmas Special.

To ease the fandoms' curiosity, BBC One just released a trailer featuring their content for the Christmas day.

Doctor Who 2015 Christmas Special "The Husbands of River Song" will air on December 25th, at 5.15 pm, on BBC One.