Still don't get it, whats the point to beat Medb by presenting an Altria book to be able to do other sorts of works if the winner is decided on the last day?

Even if they win and are allowed to sell non-altria books there won't be any days of festival left to do it or sell it

>clues are in her office
>they clearly are in a harbor on the open
>shhh I'll pick the lock
>gets close to a barrel