The view from the Tower is spectacular.
You would guess that you are at the Castle's northeast corner. I will remind the party that there are three levels to the fortification of the Castle: these are laid out below you (see image on this post). The High Bailey is about 120 feet directly below you; the Middle Bailey is some thirty yards from the base of the Tower & Castle's North Wall, and about 160 feet below you. The Lower Bailey is at least 240 - 300 feet below you and about 80 yards from the base of the tower.
If we can recall the position of Lower Gate of the Lower Bailey, where the party nearly attempted to take on the guard there, I can extrapolate the scene by defining that direction as 12 o'clock. It is, as I say, 300 feet below you and perhaps a third of a mile away. Counter-clockwise, the town of Arnsberg is beyond the Lower Gate, extending outwards from about 12 o'clock to 2 o'clock. The slope below the castle, along the far side of the baileys, forms a ridge that hides all that is behind it (including the stream the party travelled up a few days ago) runs from about 10 o'clock down to the gate. The Northwest Tower is at 10 o'clock. The principle Castle extends from 10 o'clock around to 6 o'clock. The Arnsbergerwald (forest), containing the Font-en-Breitenbruch and entrance to the secret cave, extends from about 5 o'clock to 2 o'clock. The slope from the Castle down to the forest would be from 6 to 5 o'clock.
Reversing then, to clockwise, beginning with the castle.
At 6 o'clock there is the South Tower. A central Keep in the castle sits against the mountain at 7 o'clock, and stands 80 feet (or equal with your own point of view) about 30 yards away. Between the base of the Tower you're on, and the base of the Keep inside the castle walls, there is a massive courtyard with stables and pens (6:30), fountain (7:30), workshops and storehouses (8:00) and armory (8:30). If there are kitchens, they must be inside the main keep. There is almost no activity on the castle grounds themselves. The windows of the keep are dark. The West Wall extends from the NW Tower to the West Tower, which is lower, fatter, has a number of seige engines upon it and is clearly being assaulted. You cannot see any of your Compatriots (as I will refer to the army friendly to the party throughout).
The NW Tower is connected to the NE Tower (where you are) by a 40 foot high, 15 foot wide wall, where you presume the dwarves are now fighting. This wall is built along the cliff which drops to the High Bailey, the same cliff upon which both NW and NE Towers rest. The NW Tower also overlooks the ridge that extends down to the Lower Gate; it is fatter than the NE Tower, and has numerous manned arrow slits. It is under a light amount of attack at the moment; the main body of Compatriots is fighting its way from the Lower Bailey to the Middle, though it's clear the far side of the ridge (where again you can't see) is also assaulting the NW Tower. This Tower also has a Stinger.
The assault on the Middle Bailey is moving at a run. Large parts of the Middle Bailey wall have collapsed, making places where Compatriots are scrambling upwards to join the open melee on the Middle Bailey's central fields. The Middle Bailey extends from 9 o'clock (below the NW Tower) to about 1 o'clock (far below the party). At least a hundred Compatriots are surrrounded by globes of magic Light - which makes them vulnerable to arrows, but helps hide those rushing up behind. Everywhere there are pyrotechnics, dancing lights and balls of fire (as the druid spell) ... the castle defenders have cast webs, globes of darkness and everywhere there are puffs of clouds that form, precipitate rain to soak the crumbled surfaces, and blow away again. There are patterns of hypnotic lights floating in the air, and obscuring clouds everywhere. Much more rare is the occasional lightning strike, or a flash as a fireball consumes either defenders or Compatriots. For a moment there is an ice storm. A green gas forms flows out from a lower arrowslit on the NW Tower, spreads outwards, flowing down along the ground, clearly heavier than the air. Scores who cannot escape it die what appears to be horrible deaths.
There are, of course, screams and shouts, and clangs, and the general roar of thousands of men flowing up from the valley below. And while the party watches and listens to this, the Stinger in the Northwest Tower fires, striking the boundary between the Middle and Low Baileys between 12 and 1 o'clock.
The blast lights up a path of ground some 20 feet wide and 60 feet long, as the ground itself rushes into flame; the fire curls into a mushroom some 40 feet high before dissipating; perhaps a hundred men die at once. And when the fire disappears, the ground glows red for five minutes afterwards. Men all around back away from the heat, and are forced to find another path onto the Middle Bailey. The artillerists on the NW Tower begin loading again.
Below the Middle Bailey, covering the arc from 10 to 1 o'clock, the Lower Bailey is a scene of horror. Though the light is dim, the sight is aided by giant bonfires where the bodies of humans, ghasts and a mix of both are burning in great numbers. While the original number of ghasts may have been only hundreds, they no doubt transformed more than a thousand to their number in the fighting. The white bodies beneath the flames are visible even from the Tower. There are ghasts that yet remain; they populate much of the High Bailey, in the quarter directly below the party ... there are possibly sixty of them. They are watching and waiting, taking no action, letting the defenders around them throw rocks with mangonels, or fire from the High Bailey walls.
The town of Arnsberg is fully lit. There are thousands of lights, lanterns and torches, and much magical light. Between 11 and 12 o'clock, far away, there is the straggle of the army's camp, alive with light, stretched across the valley below Arnsberg.
In the Arnsbergerwald, there's hardly any evident fighting. There are signs of torches, some moving very fast, as if to suggest mounted riders chasing one another amongst the trees. At 2 o'clock, on the east edge of the town, there can be seen the left flank of the Compatriot's army, defending the town, ready if any force should try to escape down the valley. Only the way through the forest is free of armed men - and yet the forest seems darker, more forbidding that normal senses can tell. Both Janos the ranger and Lukas the mage seem to sense there is something about the forest (for entirely different reasons) that is not quite right.
This, then, is what the party sees. I'm going to be putting up some modifiers for interacting with the prisoners as soon as I am able. Be warned that these modifiers will be applied to any attempt to coerce or gain information from the prisoners. The modifiers will be reasonable; I don't think there will be many objections.