Find Larianna Riverwind near the Scorched Grove in the southwest of Eversong Woods.
A foul taint in the soil precedes the expansion of the Scourge into a new area. The protective runestones along the border with the Ghostlands have warded the land against this taint in the past.
The westernmost runestone was destroyed during a Scourge attack, which forced us to burn the ground around it to prevent the taint from spreading.
My sister, Larianna Riverwind, watches over the Scorched Grove. Go find her; she might have some work for you.