The Doctor - Matt Smith
Clara - Jenna-Louise Coleman

Dave - Michael Dixon
Ellie - Nicola Sian
Merry - Emilia Jones
The Chorister - Chris Anderson
The Mummy - Aidan Cook
Dor'een - Karl Greenwood

Stunt Coordinator - Crispin Layfield
Stunt Performers - Dani Biernat, Gordon Seed, Andy J. Smart

First Assistant Director - David Mack
Second Assistant Director - Heddi-Joy Taylor-Welch
Third Assistant Director - Danielle Richards
Assistant Directors - Gareth Jones, Louisa Cavell
Location Manager - Nicky James
Unit Manager - Monty Till
Location Assistant - Iestyn Hampson-Jones
Production Manager - Phillipa Cole
Production Coordinator - Claire Hildred
Assistant Coordinator - Gabriella Ricci
Production Secretary - Sandra Cosfeld
Production Assistants - Rachel Vipond, Samantha Price
Assistant Production Accountant - Rhys Evans
Assistant Script Editor - John Phillips
Script Supervisor - Rory Herbert
Camera Operator - Joe Russell
Focus Pullers - James Scott, Chris Reynolds
Grip - Gary Norman
Camera Assistants - Meg De Koning, Sam Smithard, Cai Thompson
Assistant Grip - Owen Charnley
Sound Maintenance Engineers - Ross Adams, Chris Goding
Gaffer - Mark Hutchings
Best Boy - Stephen Slocombe
Electricians - Bob Milton, Nick Powell, Gafin Riley, Gareth Sheldon
Supervising Art Director - Paul Spriggs
Set Decorator - Adrian Anscombe
Production Buyers - Adrian Greenwood, Holly Thurman
Standby Art Director - Nandie Narishkin
Assistant Art Director - Richard Hardy
Art Department Coordinator - Donna Shakesheff
Prop Master - Paul Smith
Prop Chargehand - Ian Griffin
Set Dresser - Jayne Davies
Prophands - Austin J. Curtis, Jamie Farrell, Jamie Southcott
Standby Props - Helen Atherton, Rob Brandon
Dressing Props - Mike Elkins, Paul Barnett
Graphic Designer - Chris Lees
Graphic Artist - Christina Tom
Storyboard Artist - Andrew Wildman
Petty Cash Buyer - Florence Tasker
Standby Carpenter - Will Pope
Standby Rigger - Bryan Griffiths
Practical Electricial - Christian Davies
Props Makers - Penny Howarth, Alan Hardy
Props Driver - Gareth Fox
Construction Manager - Terry Horle
Construction Chargehand - Dean Tucker
Scenic Artist - John Pinkerton
Assistant Costume Designer - Fraser Purfit
Costume Supervisor - Carly Griffith
Costume Assistants - Katarina Cappellazzi, Gemma Evans
Make-Up Artists - Vivienne Simpson, Sara Angharad, Allison Sing
Casting Associate - Alice Purser
Assistant Editors - Becky Trotman, Katrina Aust
VFX Editor - Joel Skinner
Dubbing Mixer - Tim Ricketts
ADR Editor - Matthew Cox
Dialogue Editor - Darran Clement
Sound Effects Editor - Paul Jefferies
Foley Editor - Jamie Talbutt
Graphics - Peter Anderson Studio
Additional Visual Effects - BBC Wales Visual Effects
Online Editor - Geraint Pari Huws
Colourist - Mick Vincent

With thanks to
Crouch End Festival Chorus
Conducted by David Temple
The BBC National Orchestra of Wales
Conducted and orchestrated by Ben Foster
Recorded & Mixed by Jake Jackson

Original Theme Music - Ron Grainer
Casting Director - Andy Pryor CDG
Production Executive - Julie Scott
Post Production Supervisor - Nerys Davies
Production Accountant - Jeff Dunn
Sound Recordist - Deian Llyr Humphreys
Costume Designer - Howard Burden
Make-Up Designer - Barbara Southcott
Music - Murray Gold
Visual Effects - The Mill
Special Effects - Real SFX
Prosthetics - Millennium FX
Editor - Sam Williams
Production Designer - Michael Pickwoad
Director of Photography - Dale McCready
Line Producer - Des Hughes

Executive Producers - Steven Moffat, Caroline Skinner

Clara wants to see something awesome, so the Doctor whisks her off to the inhabited rings of the planet Akhaten, where the Festival of Offerings is in full swing.

Clara meets the young Queen of Years as the pilgrims and natives ready for the ceremony. But something is stirring in the pyramid, and a sacrifice will be demanded.

The wind blows autumn leaves and a wooden gate closes. One large reddish orange leaf rattles on the tree. A young man with dark hair, dressed in a suit, fumbles with an unfolded map as he walks down a sidewalk. The Doctor peers out from behind a copy of The Beano Summer Special 1981. The young man looks around in confusion when suddenly a leaf falls from the tree into his face. He stumbles into the street and the path of an oncoming car, but is pulled aside by a beautiful young woman. She asks if he is all right and he smiles.

Some time later, the two are sharing an umbrella and stumble up to a doorway in laughter. He pulls out the leaf and she asks why he kept it. He explains that, "this exact leaf had to grow in that exact way, in that exact place, so that precise wind could tear it from that precise branch, and make it fly into this exact face at that exact moment. And if just one of those tiny little things had never happened, I'd never have met you. Which makes this the most important leaf in human history." They kiss, and we see the Doctor frown and walk away in the rain.

We see Clara's father holding baby Clara, Clara playing as a toddler, and her mother showing her 101 Places to See. The Doctor is hit in the face by a football. He pops up with his hands in a defensive gesture as Clara's mother asks if he's all right. Among other things, he says that's he's possibly a touch embarrassed and seriously asks if that's dangerous. Clara's father brings her over and she's introduced.

We see that 101 Places to See, property of Clara Oswald age 9, had previously been property of Ellie Ravenwood, age 11, as tears cried by a teenaged Clara fall on the book. She closes the book, and is standing in a cemetery. Her father awkwardly reaches over. They are looking at a gravestone for "Ellie Oswald, beloved wife and mother, born 11th September 1960, died 5th March 2005". The Doctor watches and returns to the TARDIS. He reviews her file on the scanner; he's been investigating her past to make sure she's just a human girl. He declares, "She's not possible."

Clara is sitting on the stairway with her book. She hears the TARDIS land, the door open, and she smiles and jumps up as the doorbell rings. In the TARDIS console room, she asks about the nature of time ("not made of strawberries"), and if the TARDIS can go anywhere ("within reason"). The Doctor asks her where she wants to go, and she freezes, admitting that the breadth of options makes it difficult to think of one. The Doctor prompts her until she smiles and says she wants to see is "something awesome."

The Doctor walks her out of the TARDIS, with her eyes closed, into the light of an alien sun, and bids her open her eyes so that he can welcome her to the Rings of Akhaten. A golden pyramid comes into view. It is the Pyramid of the Rings of Akhaten, a holy site for the Sun-singers of Akhet. This is a system of seven worlds, orbiting the same star, and they believe that all life in the universe originated on Akhaten. Clara asks to go to it.

They wander an alien market. The Doctor says that most of the people around are local species, and points out some. He does a ritual greeting with a Terraberserker of the Cadonian Belt, mentioning that they're not common. He says he forgot how much he liked it there - he'd been there a long time ago with his granddaughter. Clara's a bit shocked at this, but the Doctor's moving fast. She runs after him and he presents her with a glowing blue fruit. She takes a bite as he scans it with his screwdriver. She shakes her head at the taste.

The place is crowded because of the Festival of Offerings, and a creature comes up to Clara, barking and growling at her. The Doctor returns, barking himself to communicate, and introduces Dor'een to Clara. Dor'een had been asking if they want to rent a moped. Clara asks what it costs and the Doctor explains that they don't use money, here. They use objects of sentimental value as currency. "Psychometry. Objects psychically imprinted with their history." She dislikes the idea, thinking it's terrible to have to give up something important to you in trade. The Doctor says it's better than bits of paper, so she says that he should pay, as someone who's a thousand years old should have something that he cares about. The Doctor pulls out his sonic screwdriver, then shakes his head and puts it back.

Clara turns her back for a moment, then goes looking for him. A little girl, wearing crimson robes, bumps into her and runs off. Shortly afterwards, two men wearing similar robes, presumably monks of the religious order of that system, ask Clara if she'd seen the Queen of Years. Clara shrugs and they search on.

Clara goes to look for the young girl, and finds her in the back corridors. The girl runs, and Clara slowly follows. They startle each other and laugh. The girl says she's hiding and is confused and skeptical that Clara doesn't know her. The girl says she needs help to hide, and Clara knows the perfect box. Three men wearing black uniforms with brass buttons and facial masks appear and start whispering, calling out for the girl. Clara takes the little girl to the TARDIS and tries to open the doors, but they were locked by the Doctor.

Clara gets a little angry with the doctor but she forgets it when the little girl ducks behind the TARDIS. She tells Clara that her name is Merry Galel, and she's the Queen of Years. She was chosen to become this as a baby, when the previous Queen died. She knows every story, poem, legend, and song of their culture. She's scared because she has to sing a special song to their god to keep him from waking. Clara tells her that everyone's scared when they're little. She had been scared of being lost, until she'd gotten lost once. Her mom found her and took her home, and told her that no matter how lost she was, her mom would always find her. Afterwards, Clara was many times scared, but never of being lost.

Merry believes Clara when she tells her she'll get the song right, and Clara takes her back to the men in red robes who were looking for her. The Doctor comes up, eating the glowing blue fruit.

In a room in the pyramid, a man in red robes sings to a mummy. He switches out with the Chorister.

Clara and the Doctor arrive to view a ceremony. The Doctor shushes Clara when she tries to ask if they're supposed to be there. There is some grumbling, then silence as Merry looks at Clara before she begins to sing a duet with the man in the pyramid. The Doctor reads the program and tells Clara that they're signing the Long Song, a lullaby to keep the Old God, or Grandfather - the mummy in the temple - asleep. There has been a Chorister singing this endless song for generations. Others in the audience hold up offerings, gifts of sentimental value, to feed the Old God. The viewers, including the Doctor, join in the song.

The Chorister in the pyramid falters, and they all stop singing, looking around in confusion. The Chorister raises his hood and continues. The ground shakes at the pyramid and in the viewing room, and a golden energy seizes Merry and starts moving her towards the pyramid. She screams and Clara asks if anyone is going to help her. She follows the Doctor, who is already leaving, saying he can't just walk away because Clara talked Merry into doing this. He replies: "Listen, there is one thing you need to know about travelling with me. Well, one thing, apart from the blue box and the two hearts. You don't walk away."

He walks up to Dor'een, barking, then pats his pockets and looks back to Clara. He tells her he needs something. She's confused, saying that he must have something himself. He pulls out the screwdriver, saying, "I don't want to give it away because it comes in handy." She looks down and quietly takes her mom's ring from her hand and hands it over. They take the moped and fly it out to the glowing ball carrying Merry. Clara almost takes her hand, but the little girl flies into the pyramid.

Clara and the Doctor land at a doorway protected by a frequency-modulated acoustic lock. He says that he really can't open it, as it changes too quickly, but he'll try anyway.

The Chorister continues to sing. Merry walks closer, saying that she doesn't know what to do. She screams. The Doctor manages to open the door, but it's very difficult and heavy to hold up. As Merry won't leave, we find that the Doctor can't do anything other than hold the door up. Merry won't leave, as she believes that it is her fault the Old God is waking, and she doesn't believe Clara anymore because Clara was wrong. Now the Old God will eat their souls. She telekinetically pins Clara to the glass around the Old God, and then says that he doesn't want Clara, he wants her, but if the others don't leave the God will eat them too. The Doctor says they're never going to leave, then hums a bar and lets go of the door. Clara asks if they've just been locked in with the soul-eating monster, and the Doctor says yes.

The Chorister is still trying to sing the god back to sleep, and the Doctor advises he run. He stops, and declares that the Long Song has ended with him. He presses a button on his wrist band and disappears. The mummy begins to move, and the Doctor tells Merry that they didn't wake him, he woke because it was time to wake up and eat Merry.

He tells Merry that she was intended as a sacrifice for the monster, because if she's going to do this voluntarily she should know why. He tells her a story about how she is unique and he believes that her sacrifice would be a waste. Merry lets Clara go and they begin to run. The Vigil appear, and Merry says it is their job to feed her to the Old God. They throw off the Doctor and Clara and lead her to the mummy. Clara rouses first and gets the screwdriver to the Doctor. He holds off the Vigil with the screwdriver. Merry sings open the secret song, opening another door. They run, but Clara goes back for the Doctor. He holds back the Vigil again as the mummy breaks the glass, and a beam of light shoots from him into the star.

The Vigil disappear, and the Doctor says they're gone because Grandfather is awake and they're no longer needed. He declares that he's made a tactical mistake. He thought that the Old God and Grandfather were the same thing (the Mummy), but "it was just Grandfather's alarm clock". Akhaten itself is Grandfather. Merry declares that the entity will eat everyone in the system and then continue across the stars. Clara and the Doctor talk about going somewhere else but she knows he's going to stay to fight it.

He sends Clara off to save Merry, and turns to confront the star. Clara returns Merry to the viewing room. Merry wants to help, so she stands and begins singing a new song. The Doctor smiles, and begins to tell a story to the Old God, a story about the people singing to him, and about the things that the Doctor is and knows. His intention is to overwhelm it with his life experience. The star begins to recede. The Doctor slumps to the ground.

The entity eats but swirls back again. Clara takes the moped back. She asks if it's still hungry, then feeds it the most important leaf in human history, which is full of her mother's lost life, a whole future that never happened. The entity feeds on the infinite possibilities represented by the leaf. The Doctor, reviving, declares that he must be full, as infinity is too much, even for his appetite. The star recedes again, this time seemingly asleep for good.

The Doctor returns Clara to her home. She realises that she'd seen him at her mother's grave. He confesses that she reminds him of someone he knew, someone who died. He gives her back her mother's ring, saying the people of Akhaten had wanted her to have it back because she saved them. She leaves the TARDIS.

[Source: TARDIS Wiki]