Greetings. Now, we are interested in your planet, as it is an oddity. We are of a mathematical nature, and oddities always interest us because they are not logical; they don't make sense. And anything that doesn't make sense to people who are interested in the abstract . . . well, we just had to come here. There is a corridor—you might call it a tube—that is open to certain places, geographically speaking, on your planet, where ships of a certain type can land, provided they fall under general specifications. The ship must be able to land and approach largely unseen. By largely unseen, I mean it cannot be seen in the visible spectrum, and it can be sufficiently disguised so that there is extreme unlikeliness that it will be detected. If some kind of latent detection happens, meaning after the fact of coming and going, that is considered acceptable. I believe there are those who have instruments on your planet that after the fact can tell at least that someone has been here. More about that later.

Also the vehicle, whatever it is, must leave a signet [such as a crop circle] upon the ground in some fashion. The signet aspect is very important, because you are all trying to remember your correlation as a soul group to the intergalactic group of coordinated souls (by this I mean the places where most of you have had at least one life) so that the likelihood of any individual seeing a picture of the signet, or even better, having some proximity physical to the signet, will be gentle, yes, but might jar your deep memory to remember who you are beyond your Earth persona.