What do "mad cows", people with neurodegenerative diseases and yeast cells growing happily on a deadly antibiotic have in common? They are all experiencing the consequences of misfolded proteins. Each organism has thousands of different proteins, which define its nature. Like origami paper, they can take the right path and fold into a swan or take the wrong path and fold into a rapacious hawk. The consequences can be deadly, leading to devastating neurodegenerative diseases in humans. Remarkably, a very similar folding process has been discovered in yeast, where it does no harm and can be studied easily and inexpensively.