Enemies from the Deep

On the planet Terranu, two families have established a research base to look for extraterrestrial life. One day four young friends spot a watery tentacle slither out of the nearby river... and a pair of eyes watching from across the water! Soon the two families meet the planet's natives, but they aren't pleased by the humans' presence. The aliens challenge them to a contest. If the humans win, they can stay on Terranu. But if they lose, they must leave immediately. It's up to