A bit of improvisation.

"Me?" Said Chadwick, looking surprised and pointing to himself. "Well, it's nice to have fans..." and with that he stood upright and walked over to the guard, who was now holding out a notepad and a pen through the bars.

When Chadwick was standing right next to him, he took the notebook. "Ah, paper...a primitive technology...do you have something to write with?"

The guard held out the pen closer towards Chadwick "Here we are" he said. Chadwick went to take the pen but grabbed the guard's wrist and with one big tug, he slammed the guard into the cell railings.

"Ugh!" the guard was stunned but was gaining composure. Chadwick grabbed the man's head pulled it hard towards the railings again, this time knocking him unconscious. As the guard slumped to the ground, Chadwick held on so as to keep the body close to the cell.

"And that is the second oldest trick in the book...Right, one of you get the keys" he said, laconically.