In one of the most bizarre science breakthroughs in recent memory, British and South African doctors have reported three cases of semi-comatose patients who were roused to a waking, interactive state by … a sleeping pill.

The effect was discovered by accident: Doctors had administered the sleeping pill, Zolpidem (better known in the US by the brand name Ambien), to calm a vegetative patient who was experiencing restless movements. “Lo and behold, he woke up 15 minutes later,” UK doctor Ralf Clauss told Nature. “The effect is amazing to say the least.”

Full story on Nature.com (subscription only) and New Scientist. Follow-up story today on the UK’s Daily Mirror, about patient Louis Viljoen.