The air is lighter here than anywhere else I have been. It is whole with the sea. Currents run unencumbered from the skies to the sea and back. I have learnt to ride those currents as marine mammals before me.
Can you follow the currents underwater, Mark asked.
Yes I can, but the machine I use underwater is different from the one I use in the skies.
Did you ever tell anyone about this, asked Gaia.
No, I did not, but some know. They have either seen me, provided me with parts, or heard stories.
Did anyone ask you about what you do, asked Gaia.
I say nothing. I say that there are many legends of flying people but no evidence. I tell my machines are sculptures. I let them discover it all themselves, if they can.
The man named Mud brought them around the garden where he built machines. They spent the afternoon pouring over designs and parts and when they left to return home to the Fiore Island, their heads were full of adventures, mammals and machines. Before Julia, Gaia and Mark parted, the man said
You are welcome to come as often as you like, but you are bound not to tell anybody what you have seen.
Minutes after they left, Gaia had unanswered questions about Mud and the machines.
Gaia, remember what the man said. Be quiet.
Don’t worry, Mark said. If she tries to talk to others about this, she’ll immediately forget it all. The only way to remember it is to keep it a secret.
helobiae 
I liked this one: “If she tries to talk to others about this, she’ll immediately forget it all. The only way to remember it is to keep it a secret.”