Oroniel fears the corruption along the river Rhachló might be more widespread.
'${PLAYER}, I shall bring this poor soul back to Felegoth. I am certain he will recover under a healer's care.
'Will you survey more of the river's length, keeping an eye out for animals that might have been affected by the river as well? The effect of the waters on some beasts is not sleep... but madness. I shall meet you again, further upstream, as soon as I am able.'
You should patrol along the river Rhachló, looking out for any beasts corrupted by its waters.
Oroniel has returned and can be found further south along the banks of the Rhachló.
You should reconvene with Oroniel and discuss how next to proceed.