Westward, Ho.

The westward trek lasts only about a day before the party’s aerial scout discerns the remains of a village ahead. Could this be the site of the slaughter that doomed the spirits at the tower? Some recon reveals that the village is occupied. Although in ruins, enough remains of a large building (an inn, perhaps) and tower and large manor house to house occupants. The inn houses ogres and perhaps small giants, the tower is stocked with a flock of harpies and there are unknown occupants in the manor house, though light leaks out from behind shuttered windows and betrays their presence. The monsters seem relaxed, unaware of the party’s presence. Indeed, the group waits the entire next day before launching a pre-dawn assault. Equipped with various means of flight, the adventurers take to the skies and head towards the highest ground – the harpy tower.
The galadin summons a meteor swarm out of the night sky and blasts the top of the tower, and as the party speeds towards the conflagration, the mage deposits a fireball into the midst of the burnt and squawking pack. The high ground is theirs! As the occupants of the inn come out they are met with more splashy magic and several die on the spot. As the front of the inn begins to burn, the group pivots towards the manor house. Taking to the air again, the mage casts a passwall spell, and they fly into the building’s interior.
There they surprise a quartet of kobolds, slay them and then embark on an orgy of bloodletting as they cut down every kobold they can find. Some perfunctory searching of the village reveals a large number of tracks headed into the Gnoll Pass and evidence of the slaughter wrought so many years ago. Slain cleric of Tyr are discovered and evidence of the treachery carried out by the once doomed spirits near the tower is also found. Some paperwork indicates that the kobolds at least were headed into the Gnoll Pass to seek employ with someone known as ‘Lord Arliss’. The letter references a keep or castle that lies in the hilly region to the south, so the group turns south.
They run across a scene of slaughter and destroy a pack of ghouls feeding on the freshly dead. One survivor is found, though her wounds are severe. She gets the cleric to swear vengeance on her behalf and the group wanders into the wilderness. A narrow track is seen by the flying mage and they embark upon it. Towards evening, they are attacked by four wyverns. Moments later the wyverns are dead and the group is scaling the cliff to rest in their lair. Plunder is found and the following day while the mage examines items, the cleric dons the eyes of the eagle and takes to the skies for some reconnaissance.
With his enhanced vision he quickly spots a walled compound overwatched by a tall tower. The place looks well fortified and the walls are heavily patrolled. The surrounding terrain has been cleared for at least a half-mile surrounding all sides of the fortifications.
Ruzzaruzzaruzzastrategizeruzza. A plan is hatched! Two days later the invisible party members fly towards the compound and note that there are signs of a great exodus. The dirt courtyard is torn up and the once indistinct trail leading to the front doors is a scar across the landscape. Many creatures left the castle in the past 48 hours and are headed northwest.
Landing at the eastern wall, which hugs the back of the tower and attached buildings, the mage deploys two passwall spells in succession, breaching one of the outbuildings attached to the tower. It is a barracks, but only sparsely occupied – giving further weight to the idea that a small army is out and about, headed northwest from here. An Ice Storm does in most of the soldiers and then is is a few minutes of savage fighting in the surrounding rooms before the group takes control although the alarm has been sounded.
They post up at the door that leads to the tower and force their way inside. They slay several defenders, including some orcs of exceptional stature before ascending the central stairs, where they face a cleric of Talos that does her best to destroy the party – to no avail.
Pressing on, the group ascends swiftly, killing anything they encounter. They gain access to what is presumably the commander’s library and begin to look for intelligence…