Cinaid identified another new target of the Free People and desires that you stop them from being able to collect the bounties that they need.
'The Nerbyg dwelling around Tol Ascarnen are a natural ally of the sapling, or so we think. Let us thin their number and ensure that they can never ally with your new pet. As an additional bonus, it seems that the Free People also have an interest in these creatures. Denying them what they need is always a benefit.'
Make your way to the waters surrounding Tol Ascarnen and kill the Nerbyg present to ensure that their natural presence is diminished and cannot call to your sapling.
Now that the Nerbyg he wanted dead are removed, return to Cinaid at Gramsfoot and inform them of the news.