Here’s a mad idea I can’t get out of my head: what if River Song ends up meeting Susan on a future Big Finish boxset? River’s already worked her way back to the Fourth Doctor, so what comes next. There are options for earlier Doctors, but what about meeting Susan?

Here’s an imaginary scene where they first meet…

INT: Castle dungeon, sounds echo into the distance

FX: A secret stone panel opens in a wall, followed by footsteps

SUSAN Stop right there!

FX: Sound of vortex manipulator trying to work but failing

SUSAN: Your device won’t work

RIVER: You seem to have me at a disadvantage. My names River Song, Professor River Song.

SUSAN. I know who you are [PAUSE] grandmother

Cue dramatic music!

So there’s an idea, but how likely is it?

Could River be Susan’s grandmother?

Here’s my idea:

• The Doctor is married to River Song (yes, not really relevant)
• At the end of Husbands of River Song, River spends a long night in the hotel with the Tweflth Doctor
• River could be pregnant and have a child left behind after the events in the library (and never mentioned? Not sure, but stranger things happen. Maybe she doesn’t know?)
• The child of River and the Doctor meets someone and they have a child Susan
• The parents of Susan find the First Doctor and leave Susan with him. Some Time Lord device / psychic gimmick lets him know this is his granddaughter, he just hasn’t help conceive her yet
• QED, Susan is River’s granddaughter as well as the Doctor’s!

In terms of modern Doctor Who, the idea can work. I know plenty of others have come up with other ideas, mostly in novels, but their canonicity is debatable (as is canon as a whole wrt the show). It’s dramatic (in my mind) and interesting. What is Susan is lying to River to make her do something for her? She could learn all about River from the UNIT files while left on Earth after the Dalek invasion. It would be fun!

What do you think? Mad or not? Let me know in the comments.