River appeared at the bars of the cell. She took out the Dalek guard earlier, and obtained the key doing so.
"You need to stop getting into trouble" She looked at Twilight, " I see you've met another after what happened to poor old Clara. So sorry about her by the way." Twilight whispered to the Doctor, "What happened to Clara?" A look of grief struck the Doctor's face, "It's... hard to explain." Twilight looked at the Doctor, "Oh, sorry." A moment of silence swept the room. River broke the silence, "We'd better hurry, the other Daleks are bound to find out soon enough." Quickly, she tossed the dead Dalek out of its war machine, and got in it. It looked very strange. There were panels everywhere that said various things. There was a large monitor displaying a video feed from the eye stalk. She saw a button that stood out from the rest that said, "Exterminate." She then maneuvered a small joystick to move the body and she drove over to the cell door. She yelled out, "Watch out!" and with a bang, the door disintegrated. River climbed out to greet the Doctor and Twilight, and then they went to the main prison room. Twilight nearly fainted when she saw it. There must have been at least a millinillion cells there. It was the single largest room she had ever seen. Ever. If you looked in any direction, you would not be able to see the end of the room. It was about 100 meters across, and the cells were personal cells, unlike the one they were in.
They dashed along a corridor, trying to be unseen, when they finally reached an exit. It was a bolted door with a large wheel in the middle to open it. The Doctor got an idea, "Stand back!: As he said that, he pointed his sonic at the door.
"But Doctor, you said the doors were sonic proof," said Twilight, "What makes you think that will work?"
The Doctor replied, "Luck"
As he said that, the sonic made its familiar sonic sound and the door flew open, only to reveal a large ball with spikes on it hanging from the ceiling. Curious as to what it was, they went to the door, but it was quickly shut. There stood a large, red Dalek, "NOT SO FAST DOCTOR." Twilight had nearly fainted. The Doctor noticed that River had a smile on her face. "What are you doing? What's going on? DALEKS! What are you doing?"
"Give me your sonic."
"What?"
"Give me your sonic." The Doctor gave River his sonic.
"Stand back"
"YOUR SILLY SONIC PROBE WILL NOT HARM ME"
"Its sonic SCREWDRIVER!" Just as she said that the sonic went off and a rumble came from the door. A second later, the door blew off its hinges, taking the Dalek with it into the abyss.