“We’ll need some of the local currency,” the Doctor said, digging through his coat pockets and pulling out a handful of coins. Some of them looked like earth currency from various countries, others were plain weird, but the Doctor dumped them all on the table and pulled out his sonic screwdriver, selected a setting, and pointed the business end at the coins.
They shimmered, twisted, contorted, and reformed, but now they shone with an unmistakeable golden lustre.
“Wait, what?” Donna stared, wide-eyed. “You turned them into gold!”
The Doctor shrugged. “Just rearranged their molecules. Alchemy’s easy for a Time Lord.”