River's voice rang out in the TARDIS' control room, even though she was nowhere near the TARDIS. She mentioned a set of coordinates twice, followed by “Doctor, please hurry!” The message she sent to the Doctor was abruptly terminated.
The Doctor spun around and rubbed his hands. “I've been waiting for this day,” he said, inputting the coordinates into the TARDIS' console. (The TARDIS, on the other hand, heard River loud and clear, and was steering herself towards River's location. But the TARDIS allowed the Doctor to input the coordinates in the console, to make him feel better about himself.) “River always insists that she doesn't need saving. Now I can save her and be her hero for once.” The Doctor checked the coordinates again, to see where he was headed. “The Planet of New Medieval France. What type of hat do I need for New Medieval France?” He paused. “A kettle hat! Wish I had time to put on a suit of armour. That would even be more impressive. But I'm sure River will be impressed with my kettle hat.”
River sent out her message to the Doctor from a castle on New Medieval France. The Doctor scoffed. The TARDIS materialized from behind the castle's door, so he didn't have to worry about crossing any type of moat or climbing anything. His sonic screwdriver scanned the castle so he'd be able to find River, wherever she was. He was confident saving River would be easy.
The Doctor's sonic screwdriver found River in a boudoir in the castle. When the Doctor found River, he put away his sonic screwdriver and prepared to make a dramatic entrance inside the boudoir.
The Doctor swung the door of the boudoir in dramatic fashion. “Honey, I'm--”
He wasn't prepared to see River covered under a thick, black, prickled plant lying on a bed. No flowers or berries grew on the plant. The prickles on the plant looked like the blades on a barbed-wire fence.
The Doctor pulled out his five hundred year diary from his pocket. He flipped through the diary. “Haven't seen these plants before in my life.”
River's chest was rising and falling underneath the prickled plant. “At least you're alive, River,” the Doctor said. He pulled out his sonic screwdriver.
The Doctor aimed his sonic screwdriver at the prickled plant. Nothing happened. The prickled plant didn't move, retract, or, break when the sonic screwdriver pulsated against them.
The Doctor looked at the prickled plant. “Not sure why the sonic isn't working. This doesn't look like wood. I'll need to try something else. I'm in a castle. There should be some weapons in here somewhere.”
The Doctor ran out of the boudoir.
It took the Doctor a few moments to go back and forth, but he was able to bring back an axe, a spear, and a sword to the boudoir.
The first thing the Doctor tried on the prickled plant was the axe. He swung the axe at a place where the prickled plant wasn't covering River's body but was covering the bed. The axe head broke when it came in contact with the prickled plant. The Doctor tried sawing River's leg free with the sword by targeting part of the prickled plant wrapped around her leg. The sword bent after a few movements. The head of the spear broke when the tip met part of the prickled plant.
“I don't have any more weapons. There has to be something else I can use.” The Doctor looked up, noticing his kettle hat. “Of course. I can try my hat.”
The Doctor took off his kettle hat and aimed it at the prickled plant. When the kettle hat landed on the prickled plant, the kettle hat split in half. The Doctor tried using the halves of the kettle hat to break the prickled plant, but the kettle hat continued to shatter to pieces in his hands.
The Doctor froze. “This shouldn't be happening.” He sat down beside the bed. “I'm supposed to be able to free you. Nothing's worked. Did you leave me a message?”
The Doctor noticed a flickering light under the bed. The Doctor reached for the light. It was River's vortex manipulator. A message flickered on the monitor of the vortex finger: RIGHT FINGER.
The Doctor looked at River's right hand. One of the prickles was poking River's right index finger.
“I free River by pulling her finger from a thorn. Just like Sleeping Beauty. Except not like Sleeping Beauty.” The Doctor shuddered. “River, you clever girl. I'm about to save you.”
The Doctor pulled River's finger away from the thorn. The prickled plant unraveled around River. When River was free of the prickled plant, the Doctor pulled her out of the bed. The prickled plant disappeared.
The Doctor danced around River when the two were out of the boudoir. “I've saved you from something!”
River watched the Doctor, unimpressed by his dancing. “Sweetie, you have something of mine.”
“I do?” He fumbled with River's vortex manipulator before giving it back to her. “Oh. Sorry, dear.”
River put the vortex manipulator on her wrist. “I was looking for an artefact from this castle. I thought it was hidden in that boudoir. As you can tell, it wasn't.”
“Did you find what you were looking for?”
“I did. You broke it trying to rescue me. It was that spear you used on that plant.”
The Doctor grimaced.
“It's okay. I'll tell my client I lost the spear when the castle imploded.”
“But the castle's still standing.”
“I'll make it implode after you're gone. Nobody will know except for us.” River looked up at the Doctor's head. “I'm amazed you're not wearing one of those silly hats.”
“I was wearing a hat. It shattered while I was trying to save you.”
“Good. I don't have to knock it off. But I have something else I'd like you to wear. Maybe a few things.”
“River, you know I have a full wardrobe inside the TARDIS.”
“I don't mean clothes, sweetie.”
The Doctor nodded. “Oh. Oh.”
“I'd prefer the TARDIS. I don't think she has a creepy plant inside her.”
The Doctor nodded. “You're right, dear. Let's go.” He took River's hand and ran straight for the TARDIS.