How does your immune system work? – Emma Bryce

The immune system is a vast network of cells, tissues, and organs that coordinate your body’s defenses against any threats to your health. Without it, you’d be exposed to billions of bacteria, viruses, and toxins that could make something as minor as a paper cut or a seasonal cold fatal. So how does it work? Emma Bryce takes you inside the body to find out.

Can you solve the dark coin riddle? – Lisa Winer

You heard the travelers’ tales, you followed the maps, and now, you’ve finally located the dungeon containing a stash of ancient coins. The good news: the wizard who owns the castle has generously agreed to let you have the coins. The bad news: he’s not quite as generous about letting you leave the dungeon … unless you solve his puzzle. Can you solve it and get out alive? Lisa Winer shows how.