An undercover cop infiltrates a group of British activists, befriending and then betraying them.

On spending six months on the southern coast of Argentina with the “Jane Goodall of penguins” and several hundred of her research subjects.

Controversy over the alleged gold standard of forensic evidence.

Scientists quarrel about the fate of animals living in the 1,600 square mile exclusion zone.

On the possibility of “fluid intelligence.”

A profile of environmental activist Van Jones.

Life and death inside a NATO hospital in Afghanistan.

On the Texas-sized trash island floating in the Pacific.

A father and his daughter’s brain tumor.

After two people are found dead in Yellowstone National Park, a team of investigators tracks down the unlikely culprit: a grizzly bear.

I’ve grown, over the last few months, the beginnings of concerned; he’s started to suffer bouts of malaise. Nothing too regular, or too terrible: mild stomach aches, sore joints, general lethargy. In anyone else, it could be anything, etc. In Chad, I grow attuned to the slightest variation in temperature, to the distracted look behind his eyes when food isn’t sitting with him.

How the CIA, under a program called MK-ULTRA, used a San Francisco apartment to dose johns with LSD.