Polly walked down the hall at a brisk pace, trying to keep ahead of Ben.
"Now look duchess, you know I didn't mean to do it," he said, trying to get her to look at him. "It was an accident!"
"That's no excuse Ben Jackson!" she snapped. "Now, I'm going to get the Doctor!"
"But you know what he'll do to me! I'll be lucky to have my skin still attached!"
"Well, it's your own fault!" she exclaimed. "I personally think you've got everything that's coming to you."
"But Polly…"
"What's all this shouting about?"
Both of them froze as the Doctor walked around a corner.
Polly bit her lip. "Well Doctor, Ben… did something."
Ben groaned.
"What did he do?" the Doctor asked.
"Well, he…"
"Alright Duchess, I'll tell him," Ben interrupted. He took a deep breath, but didn't say anything.
"Well, what's wrong?" The Doctor asked, nervousness growing in his eyes.
"Well… you know that door that you told us never to open?"
"… yes…"
"Well… I opened it."
"… and?"
"Well, I accidently dropped one of the bottles that was on the shelf."
The Doctor's eyes widened. "Which bottle?"
"Well, it was the red one."
"Ben, that was pure Trianice acid, it's very…"
"And then I threw water on it to clean it up."
"YOU DID WHAT?" the Doctor shouted.
"So now the floor's covered in this weird foam…"
The Doctor didn't wait for Ben to finish, and ran down the hall and disappeared. A few seconds later, he came back, practically sprinting.
"Run the both of you! Run!"
Ben and Polly did as he said, just before a wave of pink foam washed into the hall. All three of them were swept up and carried away. Finally, they ended up in the console room. The Doctor grabbed the console, and held on as the waves of the stuff crashed over him. Polly, screaming at the top of her lungs, managed to grab one of the roundrels, and was hanging on for dear life. Ben, on the other hand, was pushed up against the wall, where he was quickly buried under the foam.
"When Trianice acid is mixed with H2O," the Doctor shouted, "it creates a foam substance that expands and increases in size for a full three minutes. Very fun a children's parties. Just hold on you two, it'll be over soon."
Polly nodded, and actually started to smile. Ben managed to get out of the stuff and wave his understanding, before he was buried again.
The Doctor pulled himself higher on the console. "Poor Jamie… wherever he is, he must be extremely confused."
I'm not sure where this came from. It's just the idea of the Second Doctor slipping and drowning in foam (from the 'Seeds of Death') is a really funny image. And Ben is nosey. And Polly is a tattletale.