"The Cove" is a movie about dolphins. There is a special kind of dolphin called the "Taiji dolphin," and they live in a place called Taiji, Japan. The movie is all about how people want to catch these dolphins and sell them to places like SeaWorld, where they can perform tricks for people to watch.
But the movie is also about how dolphins are really smart animals and they don't like being kept in small tanks or being used for entertainment. So some people in Japan, along with some other folks from other countries, want to try and stop the people who are catching Taiji dolphins.
The movie shows how they sneak into Taiji and try to film what is happening to the dolphins. It's really hard for them to do this because the people who catch the dolphins don't want anyone to see what they're doing.
Eventually, they find a secret cove where the people who catch the dolphins are hiding them. When they get in there, they see that the dolphins are being hurt and killed in a terrible way. It's very sad to watch.
So the people who made the movie are hoping that by showing everyone what is happening to the Taiji dolphins, more people will want to help the dolphins and stop them from being caught and killed.