I had two more short ideas for stories that took place in this season.

Martha Idea

Martha, while investigating supernatural phenomena in the southern United States, gets thrown back in time, along with a group of monsters who look a lot like devils. Remembering what happened with the Weeping Angels last time, she sends a message forward in time to the Doctor, asking for a rescue.

In the meantime, Martha explores. She gets into trouble due to her dark skin, and winds up running for her life. But she's saved by a kindhearted churchman named Philip. Philip is a preacher, and a virtuous and pious man, and he takes her back to his house and protects her, giving her a place at the table with his family.

There, she meets Philip's little son, Caleb, a quiet and strange boy. Philip is clearly trying to teach his son to choose good over evil, and to follow the way of the Lord. "Every Eden has its snake, Caleb," says Philip. "Don't you forget 'bout that."

Caleb is a strange little boy. And Martha knows it. She talks to him, aside, and Caleb admits (a little shyly) that, "Sometimes, I hear the voices of dead spirits." Then adds that his daddy doesn't like to hear about that, because his daddy says it's the devil's own voice, and Caleb should reject it.

Then screams start up outside.

Martha hurries out, and realizes that the devils have followed her back in time, and are here. Now. Ravaging the town.

Martha runs outside with Philip, and tries to save as many as she can. The devils destroy nearly everything, and nearly kill Caleb — who is fascinated by them. Martha sweeps little Caleb up into her arms, while Philip shouts at everyone to, "get to the church!"

They run to the church, and barricade themselves in.

The devils soon discover a back-entrance, and Martha tries to fend them off. She's about to fail… when there's a flash and all of a sudden, Seo and Jenny appear out of nowhere! They help the others fight off the devils, and patch up the broken barricade.

Philip praises the women for their help, claiming they are "angels, sent by the Lord, to help us in our time of need!"

Then, noticing his son's continued fascination with devils, scolds little Caleb. "Keep your eyes away from the devil, my son! Seek only the light, and never the dark!"

Seo stares at little Caleb. She can't help but think… she's seen him somewhere before.

"But how did you two get here?" Martha asks Seo and Jenny.

Seo is torn away from trying to work out why Caleb looks familiar, and instead, she and Jenny explain. "We got your note! In the future!"

"Dad's still back there, trying to work things out on that end," Jenny agrees. "And sent us here, to investigate and help him out!"

Apparently, this isn't just your normal monster invasion; this whole period of history has been time locked with a rather crude lock, and they need to find out who locked it and how, so they can send the Doctor that info in the future, and he can find some way to undo it.

Then people start dying.

They die horribly, and many of them die in front of little Caleb — who is emotionally scarred for life. Too late, Seo and Jenny realize that the devils can actually shift their shape so they take on the appearance of villagers — in particular, young women.

They want to stay and fight back, but Philip forces them to leave the church.

"I'll hold them back, and protect my town," Philip insists. "Just go outside. Find whoever's behind this. And close this chasm to Hell, forever!"

"Chasm to Hell!" Seo realizes. "Can it really be that easy? Is it really just a Hellmouth?"

They head off, and discover that it's actually one of the rare temporally active Hellmouths in the United States. They find the person behind the Hellmouth, who is probably a Torchwood monster that everyone thought was defeated, and they fight.

Through something immensely clever, Seo, Jenny, and Martha defeat the villain.

And through defeating him, they wind up sealing off that particular Hellmouth, forever.

Meanwhile, back at the church, Caleb watches the rest of his town die at the hands of young women. Then sees his father, Philip, get ripped apart and brutally murdered by them, trying in vain to fight back and believe that the Lord would save him.

Caleb hears a whisper from the shadows, telling him to come into the darkness, and he would be safe.

Caleb scuttles into it… and realizes that the evil women couldn't see him.

"Good couldn't save them, little Caleb," says a voice that echoes all around him. "All those wicked, evil, sinful little girlies would have ripped you apart, if it wasn't for me."

Caleb then sees his father, as if risen from the dead. Except it isn't really his father at all.

"Thing is, Caleb, it don't gotta be like this," says the First, disguised as Philip. "Them three girlies, who brought those devils here with them — they're from the future. Change the future, make sure they die before they can come back here… and all this will never have happened."

Caleb jumps to his feet. "How do I do it?"

"Easy." Philip stretches out his hand. "There's one little girly worse than all the others. Whore of Babylon. Her name… is Buffy Summers. And if she don't never grow up — then Jenny, Seo, Martha, they'll all die."

Caleb remembers this name forever.

His enemy.

Buffy Summers.

"And all you gotta do to kill her… is accept my influence," says Philip. "Cuz you and me, little Caleb — together, we're gonna wipe out the Slayer Line. For good."

Caleb accepts. And is joined with the First.

.. .. .. ..

Fenric idea

We open with a scene of Jenny and Seo playing chess in the TARDIS. Jenny is winning, but doesn't look terribly happy about it. Seo, meanwhile, is constructing an intricate and carefully balanced tower with the pieces that both she and Jenny have captured, throughout the game.

"Hmm… need something with a fairly balanced center of mass, next," Seo observes, looking at her structure. Then she turns to the chess board, and strategically maneuvers just the right piece into place so that Jenny will capture it.

And Seo will get another piece for her structure.

"Seo, this isn't how you play chess!" Jenny snaps, finally giving up. "You don't lose the game on the board so that you can create complex structures off the board!"

Seo makes Jenny's move for her, grabbing up the needed chess piece. "Who says?" It balances perfectly. "I prefer to play chess this way. I'm rubbish at the other way."

Then the TARDIS hits a jolt in the vortex, and Seo's intricate sculpture crashes to the ground.

The Doctor races in, frantic. "Time storm!" he shouts. "We've been caught right in it!" He tries to gain control of the ship, but can't succeed. "Hold on tight!"

They do.

The TARDIS lands in Fenric's domain.

.

At the same time, back on Earth, another timestorm attacks A Charitable Earth.

By the way, by this point, Ace and Dawn have set up A Charitable Earth in order to protect Donna, and give her something to do that won't bore her so much that she seeks out trouble and gains Doctor memories, but will protect her from getting the full amount of Doctor memories.

Thus, Donna is able to be happy. But not die.

Donna believes she's working to organize charity events and help fight terrorism. Not to fight aliens.

So… back to the story! A time storm hits A Charitable Earth, and the others only just manage to get Donna out of the way in time. However, in doing so, Ace, Dawn, and Shaun are all scooped up and dragged away from Earth.

They arrive, like the TARDIS, in Fenric's domain.

.

Ace immediately understands what's happened. She explains it to Dawn and Shaun, helping them to navigate through Fenric's world.

Then they bump into the Doctor.

"Professor!" Ace cries. Then, a little worried, "Tell me this wasn't some brilliant master-plan gone wrong."

"Course not," the Doctor says, a little affronted. Pauses. Then, reconsidering, adds, "Unless it's the result of a brilliant master-plan I haven't thought of, yet, going wrong in my own future."

Ace warns him that she still has a baseball bat.

And she knows how to use it.

Then Jenny goes all funny, and her eyes glow gold. No one understands what's going on — except for Ace and the Doctor, who are outraged.

"You leave Jenny alone, Fenric!" Ace demands.

Yep, you guessed it — the gold eyes mean that Fenric has possessed Jenny. Fenric, speaking through Jenny, laughs. Pointing at Ace, calling her his "pawn."

"The child of the baby," says Fenric. "You've been working for me ever since. I plucked you from the Time War, just to make sure you could save two people from certain death and doom."

Fenric points at these two people, in turn.

"Dawn Summers, from the knights of Byzantium," says Fenric. He points at Seo. "And Seosyrae Summers, from floating through the Irkoli galaxy as a statue forever."

Ace feels cold. She shudders.

"You are my creature," Fenric tells Ace. "By saving both of them, you have created an unbreakable link between me… and the Key." He steps forwards, stretching out his hands towards Seo and Dawn. The hands radiate with power. "Time to collect my prize."

Seo and Dawn shriek, as they find themselves being dragged towards Fenric — unable to do anything against him.

The Doctor dives into the way, stepping between Seo/Dawn and Fenric. "I challenge you to the one game you can never resist!" says the Doctor. "A game of chess!"

Fenric scowls. But the Doctor's right, he can never resist that game. "You always think yourself the chessmaster, don't you? Standing behind your soldiers, commanding your army from afar."

"Oh, don't get into the melodramatics with me, Fenric!" The Doctor says, with a sigh. "I heard it all the last few times we faced off with one another." He claps his hands. "So! Here are my terms. If I win, you let us all go. If I lose — you get the Key."

Fenric lets go of Seo and Dawn. "No," he says.

The Doctor is shocked. "No?!"

Fenric drags Seo forwards. "If she wins, Doctor, then you'll all win your freedom," he says. "If she loses… the Key is mine."

"Me?!" Seo shakes her head. "But I'm rubbish at chess!"

"She is," the Doctor agrees. "Completely rubbish. What's the fun in playing an opponent that's so easy to beat?"

"I don't want 'fun'," Fenric replies. "I want the Key."

He sets up the board, and the Doctor discovers that he's one of the pieces on the board. His TARDIS is another. And Shaun and Ace are still more. Dawn is, for obvious reasons, Seo's 'King' piece.

"You're not the chessmaster anymore, Doctor," says Fenric. "Your fate is in someone else's hands."

.

There follows a bizarre chessy kind of thing, during which Seo loses the match spectacularly, but only so she can assemble the pieces off the board and use them in the end.

See, Seo realizes that if she loses certain pieces in certain ways, she can actually send those pieces back to Earth.

So she loses Shaun and Ace immediately.

Shaun and Ace wind up back on Earth, but they don't land where they started. Instead, they find themselves right outside of the Slayer Institute. There, they wind up running right into a bunch of Haemovores, which Fenric's sent to Earth in order to destroy the escaped pieces.

Shaun freaks out, but Ace knows exactly what to do!

She runs into the Slayer Institute, and grabs up one very important Slayer, bringing her out in front of the Haemovores and showing her off for all to see.

"That's right, Haemovores!" shouts Ace. "You can't kill me! Because I've got… Faith!"

Faith is completely shocked that her mere presence is enough to scare the Haemovores away. "Wuss-vamps," Faith says, as she launches herself at them. "Hey. Sounds good to me."

Strangely enough, everyone else at the Slayer Institute finds the Haemovores almost impossible to defeat. But Faith defeats them all easily.

"Because when you're facing Haemovores, the best weapon is Faith!" Ace explains, laughing at her own little joke.

(She does, at some point, explain. The key to defeating Haemovores is to have complete, unbreakable faith in something. The Doctor explained this to Ace as, 'You can defeat the Haemovores if you have faith.' Ace has realized that she has Faith Lehane, who is a slayer with a complete and unswerving faith in her ability to slay vampires. Her name and her belief in her own abilities make the Haemovores no match for her.)

.

Back in the game, Seo maneuvers the TARDIS onto a position, on the board, that Fenric can take. Then manages to lose the Doctor in a similar way.

.

The TARDIS materializes on Earth, and the Doctor steps out. He's impressed at how Ace has managed to use Faith to defeat the Haemovores, and wonders if he can't use a similar trick on Fenric.

He and the others devise a careful and complex plan that will use the Cleveland Hellmouth to defeat Fenric — the second activates the Key.

.

Fenric beats Seo at the chess game.

"Check mate," says Fenric. He grabs for her. "Now… the Key is mine. You are mine."

"Then let Jenny go!" Seo begs him. "You don't need her, anymore."

Fenric does so, and Jenny goes limp.

Dawn freaks, running over, thinking that Jenny is dead. However, it turns out that a Time Lord brain is no match for Fenric, and although Jenny was possessed, she's not dead.

Then Dawn realizes that Seo's been possessed, instead.

"All I need is your blood," Fenric — through Seo — tells Dawn, grabbing her up. "And I can create a portal that'll swallow up the universe. All life will be my life. All creatures will be my creatures. I will become the portal, and I will become the essence of all things!"

He prepares to kill Dawn.

But Jenny charges into him and his knife misses — just cutting Dawn instead of killing her.

The cut is enough. The portal swirls open, and Fenric takes possession of it. He creates a time storm along its edges, trying to turn the whole universe into his own little chessboard.

Fenric gets up, and makes a sweeping gesture. A thousand Haemovores appear from nowhere, surrounding Jenny and Dawn.

"Tear Jenny apart," Fenric commands.

.

Back on Earth, the Doctor uses his TARDIS to connect the portal into the Cleveland Hellmouth. He shouts to Faith, "Now!"

Faith dives into the Hellmouth, as it starts to glow.

.

Faith pops out in Fenric's realm, fighting off the Haemovores with ease.

"Better spread the news, Fenric," says Faith, staking a Haemovore expertly. "Humanity's got Faith. And that's enough to kick your ass."

Faith's fighting distracts Fenric for long enough that he doesn't realize what's happening to his portal. It's only when it's too late to correct the error that Fenric discovers… the Doctor's linked his portal to the Cleveland Hellmouth.

That means Fenric isn't about to control the universe.

He's about to trap himself inside the Hellmouth.

"You should have realized!" Jenny shouts, as the portal sucks Fenric — and Seo — towards it. "My sister never thinks of the pieces on the chessboard! She only plays for the pieces off it."

Fenric, in Seo's body, is sucked into the Hellmouth.

The moment it swallows Seo, it closes.

But Seo, as it turns out, has fought back against Fenric during that whole time. She got just enough control to shove him out of her mind and send him tumbling into the Cleveland Hellmouth, then slam the portal shut as she fell through its mouth.

She just barely missed being sucked into it.

They all get together, and find a way to return to Earth. The Doctor compliments them all on a job well done!