An adult human can distinguish up to 10,000 odors. You use your nose to figure out what to eat, what to buy and even when it's time to take a shower. But how do the molecules in the air get translated into smells in your brain? Rose Eveleth charts the smelly journey through your olfactory epithelium and explains why scent can be so subjective. [Directed by Igor Coric, narrated by Rose Eveleth].