In the city of Ert'Aria lives the young inventor Leicester Maycraft. He is part of a small adventuring clan called Oasis led by Carina Verritti, the daughter of the Archduke who rules over the city. Later that evening there is to be a regular meteor shower that comes once every seven years, and the clan is preparing a party. They meet a young puppeteer named Agnes Boulange who makes an impressive show of her magical automata puppets in the square. They also meet a young knight named Chelsea Arcot and the sisters Ritos and Salsa who run the Tortilla shop in front of their clan hall.

It has been some time but apparently the Ale meteor shower is still going on. This concerns the Archduke so he sends Oasis on a new quest to investigate the phenomenon. They are asked to visit the forest home of Mise Altoise, Agnes's teacher for possible clues. Agnes is familiar with the area and knows how to get through the maze of magical traps her teacher had set, but notices that they have been changed in subtle ways, so she expects Mise to be there, and is disappointed to find that she is not there. Oasis searches the house and finds a note for Agnes hidden in a secret compartment. Meanwhile, Nick, standing guard outside the house is attacked by a girl who proves to have exceptional fighting ability.