There are two messages: the Princess note in the Maid's room (castle first floor left) and the note in the Princess's room in the separate tower. Both should go into your item bag.
You show her a secret message from the Princess. You find it in the Maid's room (castle first floor left).
Go to the fountin and click on the souler system panel and enter the code
The secret message from the Princess is in her Maid's room (castle, first floor left). There is another note by the Princess in the left tower which is now disconnected from the castle. (see related question)
If you have the Secret Message from the Princess (from the maid's room in the castle), the mill girl will give you the password to the secret room below the fountain. (see related question)
You need the Princess's secret message from the maid's room (castle first floor left).
There is no wishing well on Astro Knights island. There are :The spaceship fountain - there is a gold coin in the water, and if you take the secret message from the castle to the mill, the girl there will give you the password to open the secret passage under the fountain.The underground lab - Mordred's secret lab is hidden under the two bales of hay on the farm, and you will need the key from the secret room under the fountain.
On the first floor of the castle, left side door. There is a secret message there, as well as a mechanical mouse. (see related question)
There is no wishing well on Astro Knights island. There are :The spaceship fountain - there is a gold coin in the water, and if you take the secret message from the castle to the mill, the girl there will give you the password to open the secret passage under the fountain.The underground lab - Mordred's secret lab is hidden under the two bales of hay on the farm, and you will need the key from the secret room under the fountain.
None. The Maid's room (castle first floor left) has the secret message, which you take to the girl on the upper floor of the Mill.
go to the secret door
The plaque is on the fountain outside. It has various planets, stars, and moons on it. (You will need to take the Secret Message to the upper floor of the mill to get the password symbols.)
The Queen gives you planetary coordinates when you accept your quest. The secret message is in the Maid's room (first floor left in the castle). The missing journal page is under Mordred's bed on the second floor of the Museum (see related question).