Das Voynich-Mysterium

You must change the active double page to a different spread each turn (except your very first turn), and you may not have the same active spread two turns in a row (the golden rule). (page 9)

To progress a page you must return the Research token(s) specified by the page's progress condition (if multiple tokens are required they must come from different zones), gain the Overall Knowledge shown, then rotate or flip the card as the arrow indicates and return it to the sleeve; you may progress pages before and/or after performing actions and as many times as you can fulfill the conditions. (pages 10–11)

If you place a Water drop on a root tip that already has one, your Water drop immediately moves along the arrows to the next empty space and gains the reward on the space it lands on (only one Water drop may occupy each root tip). (page 13)

For each Knowledge sharing token you return you take a matching-type Puzzle piece and must place it orthogonally adjacent to an existing placed piece, taking the piece with the letter that matches the space and flipping it so the letter is hidden; after placing pieces you may move one of your Research tokens onto one of the pieces you just added. (page 22)

Tokens are limited: when you add a token you may take it from your supply or from a different section of the main board, but not from the same section you are placing into, and if an action is triggered by placing a token you cannot remove that exact token to pay the cost — you must use a different token of the same type. (page 12)

No — only the colored Knowledge tracks (Botany, Astrology, Baths, Writing) give Knowledge sharing tokens when you reach or pass their breakthrough icons; nothing happens when your Overall Knowledge marker reaches a breakthrough. (page 12)