Hello, Liz and Gus. We know where you are now. We also understand that you hope we can land somewhere near you. But we can't land the mothership in the forest because there are too many trees. You must get to the landing site in less than 48hours. We're coming to get you as quickly as we can. Please stay calm.

Now listen carefully. This is very important. Look at your map. Can you see square B4？ Your spaceship is there. There's a river near you, in square C4.The river goes into a lake in B2, C2 and D2. There are some mountains next to the lake in E1,E2 and E3.

We're going to land the mothership in square D1. This is important to remember—— square D1 is our landing site. We can't land in A1, B1, C1 or A2, because there's a desert there. Since there's a town in D5 and E5, we can't go there either.

We will land the day after tomorrow. You must get to the landing site in 48 hours.Then we will take off.

You can only carry the most important things with you. You must leave most things behind. It's not always easy to decide. I hope you can make it！Oh, one more thing.Remember that you mustn't hurt or kill any living things on this planet.

Good luck！