Seek out Shadowstalker Ickoris at the Warsong Farms Outpost west of Warsong Hold.
<Hellscream shakes his head.>
You may not have noticed that we're trying to win a war here, [race]. I need all available soldiers at the primary points of conflict. This means that we don't have any real soldiers to spare for these minor incursions.
<Hellscream pauses to think.>
If Barthus wants reinforcements at the farm...
<Hellscream claps his hands together.>
...he shall have them! Report to Barthus's assassins at the farms, west of here. Let them know that reinforcements have arrived.