"You know why trees smell the way they do?" Murphy asked, looking up from her hammering: "Sap?" Logan guessed. "Chlorophy!!?" Murphy shook her head. "Stars. Trees breathe in starlight year after year, and it goes deep into their bones. So when you cut a tree open, you smell a hundred years' worth of light. Ancient starlight that took millions of years to reach Earth. That's why trees smell so beautiful and old."