Everything here is the same underneath. The maps, the stations, the gates and the pages hold one set of rules — the ones people actually found, in the order they found them. What changes with the character you choose is the world the rules are told in: a parchment map, a ship's log, a source tree, or the museum after closing. Read a station five times in five worlds and the rule is the one thing that never moved. That is how you know you have it.

Three ways in. The Quest climbs the maps level by level. The Games take one wall each and let you hear it, see it or touch it. The Helper takes the school's own books page by page and gives every rule its purpose back. They meet on the stations: a game and a page both hang on the station they belong to.

Every map has the same shape. A core in the middle holds what the subject already knows how to do and the kind of question it keeps asking. Four axes run outward, and every step out along an axis is a wall the previous step could not get past. The applied fields sit outside the circle — in the book they are where units begin, because that is where the walls come from.

The journey is not the axis order. The numbered stations follow the order in which people actually reached these ideas: fractions long before negative numbers, mirrors long before lenses, metals long before atoms. That zigzag is the point — following it keeps every purpose attached to its tool.

Levels. Stations are grouped into levels. A station counts as done when its gate is passed — four questions, all four right, as many tries as you need. The next level opens only when every station in the current one is done. Where a unit has not been written yet, a plain "mark done" box stands in for the gate.

Discovery layer. The switch in the top bar adds time to the maps: a year slider, the path people actually took (dotted), the area that was known by that year (shaded), and an Origin note on every station telling how it was found. Path and area can each be shown or hidden.

Bridges. Where one subject borrows from another — the sine of an angle inside the law of refraction, the balance scale inside the conservation of mass — the two stations are linked in both directions. The bridges below are the whole list.