I don't believe it! It's my uncle! He reached the moon first!!!! But how??

We let him in the airlock and he explains.

For all the months that we were in America building the gun, he was in London experimenting with the Martian flying machine. He finally got it to fly again, and used the parts to make his own moon capsule!

He had one flying plate left over, and we can use it to get our own missile back to Earth!

He says the plate is very difficult to use, and once we are off the moon again it might stop working. But if we use it right now it should get us started.

The others look around at the dead, airless world, and decide it is wisest to take up his offer. Uncle says he's found a large crater filled with soft mud - maybe evidence of water on the moon? I can't get excited about mud.

Should I join my uncle and explore the mud? What if he's right and the flying plates stop working at some point? Should I return to Earth with my friends while we still can? Or should I something else?