Disclaimer: It all belongs to BBC
The Doctor sat a workbench, staring blankly at the far wall. His hands however, were working furiously. He felt each piece of laid out material carefully as he worked: screwing them together, connecting wires, fitting curved pieces of metal together. "Almost done..." A smile graced his face as he held up his finished product.
"Doctor? What're you doing?" He raised his brow as Rose entered the room.
He turned towards her voice and grinned like a five-year-old. "This," he held up the device to her, "Is what I call an echo-glove." The glove looked like a solid metal bracelet with a single clasp. Five rings with glowing red bands were connected to the bracelet by slim chain-encased wires.
When no immediate reply came from Rose, he continued. "See, you humans use canes to make sure you bump into anything if you can't see. This thing works to the same purpose, only more advanced. The rings will send out sonar waves that bounce back off of objects and be converted to psychic pulses by the technology in the bracelet, which my brain can read and identify!" Slipping the glove onto his right hand, He turned in Rose's direction and waved his hand at her. "Just like a bat!"
Rose chuckled, smiling widely for the first time in a good while. "Like a bat?"
"Like a bat."