Opium

Some doctors' manuals from the 19th century do list Lactuca virosa as a pain reliever, but there's little evidence that it works.

• By Francie Diep

Genetically engineered yeast will soon be able to make morphine from sugar. Tech policy experts fear a generation of Walter Whites.

• By Kate Wheeling

Who are the true believers in crop circles? And might they be on to something?

• By Katie Heaney