Captain Kirk’s crew has stolen a cloaking device from the Romulans, but when they attempt to hold the Romulan Commander hostage, they find out just how dangerous she is.

A mysterious visitor, Seven, tries to convince Captain Kirk to let him disarm a nuclear missile/warhead that is heading for Earth. With Spock unable to do it himself, the crew is left with no choice but to trust him.

Spock and McCoy have traveled through time, but have lost the portal they need for their return. Time is running out and Captain Kirk hurries to bring them back to safety. For Spock, this means saying a difficult goodbye.

When humanoids with powers to control the ship challenge the order of command, Kirk must maintain his authority and keep them firmly in line, all while calming the nerves of his anxious crew.

Let's find out more about an American activity aimed at school kids: the spelling bee. What is it and how does it work?

Sigrid talks about "The Elementary Spelling Book" by Noah Webster, which was the basis for the American English dictionary and a big part of the development of spelling bees in the United States.

Sigrid explains how a spelling bee normally proceeds. There are fixed rules and there are options.

In recent years, we've seen an increase in the intensity of tropical storms and hurricanes due to global warming. But how and why do hurricanes form? Sigrid provides a basic explanation of this phenomenon.

We continue to explore the phenomenon of hurricanes. Why are they so dangerous? And do they serve any purpose?

Columbus Day has always been a controversial holiday in the United States. In this video, Sigrid goes back in time to get some historical background, which sheds a new light on its significance.

Most Americans don't realize how Columbus Day came to be a national holiday, but it actually doesn't have that much to do with Christopher Columbus, and we might even recognize a connection to present-day events. To recall something Mark Twain once supposedly said, "History doesn't repeat itself, but it often rhymes."

The European Union has been in the news a lot lately, so let's take a look at what it's all about. What is a "union" and what's the purpose of this one?

Let's have a look at which countries are members of the European Union and where they are on the map.

Every day, we get information from lots of different sources. But how do we know what is true and what is "fake news?" In this 3-part series we explore different kinds of information and misinformation.

What's the difference between disinformation and misinformation? And what about misleading information? Find out in this video.