You've had a stroke that means you're paralysed - unable to move your arms and legs.
But then scientists build an electronic gate into your brain that means you CAN move a robot arm - just by imagining the movement in your brain.
You get so good at it you can control the robot arm to bring a cup of coffee to your mouth and drink the coffee from a straw.
You'd smile wouldn't you?
Well just look at the video and watch the amazing smile spread across Cathy Hutchinson's face as she does just that.
16 years ago, she had the stroke that left her paralysed, unable to speak, but mentally agile. Five years ago doctors surgically implanted electrodes into the area of her brain that controls movement - the motor cortex.
When she imagines moving the robot arm, the nerve cells in the motor cortex respond. The electrodes pick up that response, pass it through a small box on the top of her head to electronics which decode the signals and move the robot arm. Hey presto the coffee cup arrives at her lips.
No wonder she's smiling.
Ok, this is a long way from a practical system that could help lots of people paralysed by strokes or spinal injuries. But neuroscientist Andrew Jackson from Newcastle University told ITV News he can foresee a day when future devices could be practical for many people.
They would use electrodes that are on the skin, not implanted, to avoid the risk of infection. They'd be wireless, sending signals just like your mobile phone. And the electronics that decodes your thoughts would be miniaturised.
But best of all, in future these electronic gates wouldn't control a robot arm - they'd control your own arm. Or your legs so you could walk again. Who knows how long it will take to get there. But researchers are on the road and Cathy Hutchinson's name will go down in history.