Sorry I botched that!
I was using the wisdom roll as both a check to see if your characters discern any of the 'babbles' of the brook and at the same time the roll doubled as a saving throw to avoid the enchanting mesmerizing effects of the waters. So if you succeed you would discern words and keep your wits but if you fail you would be mesmerized and under the spell of the brook. And I always play that saving throws can have critical fail. And I actually forgot that is not the rule. I'm sorry. Since I wasn't clear at all, please ignore the crit business I spoke of. My error.
Instead assume that Regan and Cordey just can't make out anything that the brook seems to babble, but nothing else happens otherwise.
In Admiral's case let's assume he made a successful wisdom check to discern something that the brook speaks of. (And his crystal gives him extra protection against enchantment effects.)
I'll get the next post up tomorrow!