As Arachnar lets out his final death hiss, you notice a blade buried to the hilt in his underbelly. Upon closer examination, you find "Mansfield" inscribed on the blade. Perhaps someone at Crimson Wash will know where it came from.
This sword belonged to the famous bard Timot Mansfield who traveled this way not long ago. I hope all Arachnar took was his sword, and not his life. Either way, he found the wrong cave in which to make camp.