Ok, here is my pitch for one of the specials to be set after series 4.
Lord of the Reedy River
The Tardis lands in a forest clearing, the sunlight gleaming down in shafts through towering trees.
"So where are we?" Ben asks puzzled.
The Doctor had paid a visit to Cambridge earlier that day and met with Ben and Kyle in the Mermaid Wine Bar. Ben was feeling down as his boyfriend Anselm wasn't replying to his texts and the Doctor had decided to invite him to rejoin the Tardis team, bringing Kyle along.
"Who knows", the Doctor replies to Ben,
"I set the year to random. More interesting that way. Its earth though."
"Thats rather irresponsible. What if we've landed in the middle of World War Two or something?"
The Doctor is unimpressed:
"Ah thats nothing. Been there & done that with Rose. You know, the attractive companion."
He opens the Tardis door and strides out, breathing in the sweet forest air.
Meanwhile, in nearby Nottingham Castle, the Sheriff is pacing up and down looking worried. "What is all this nonsense Gisbourne. You say you're men are too scared to go out into the forest looking for Hood and his men in case it gets dark? Dark? Ye Gods man, what are they, men or mice?"
Sir Guy is adamant:
"You don't understand sir. The thing... it comes out of the river at night. Some say its a demon conjured up by Hood and his men with their pagan rituals. The bodies are always mashed to a pulp. The peasants won't leave their straw huts after dusk."
The Sheriff scoffs:
"Ha, supersticious saxon knaves! Its probably just a wolf. Still, make sure you keep spreading it around that its a forest demon conjured up by Hood. The villagers are all against him now. Soon we'll have him and his not so merry band all hung & gibbeted. Ha ha ha ha....."
The Doctor, Donna, Ben and Kyle are walking through the forest. The Doctor is whistling to himself.
"Look, have you any idea what year it is?" Donna asks.
"How should I know you daft old cow. I've told you, I set it at random."
"Hey, who are you calling a daft old cow?"
"Obviously you since I'm talking to you."
Meanwhile, Kyle and Ben are talking:
"So have you ever been to this Doctor's home planet like?"Kyle asks:
"It no longer exists. Destroyed in a war. Gone. He's the last of his kind."
Suddenly the Doctor hears something and ushers them to a halt.
"Shhhhh. I'f I'm not mistaken we are surrounded."
"Who by?" Donna asks:
"Oh I dunno. But I suspect we are about to find out......
Jumping down from the trees are the outlaws, led by Robin Hood who strides up to the Doctor with a grin on his face......
....... to be continued.