As the new arrivals take in the astonishing view from the tower's arrow slits, and waterskins an food are passed around to those who are famished, Gareth outlines the situation: a wooden bridge arcs away from the double doors on the west side of the tower they currently occupy, crossing a 40' deep rocky chasm. There's a stone gatehouse on the other side of the chasm, the entry of which is blocked by an iron portcullis, the bars of which have been bent apart to allow something big to climb through. "Oh, and watch your step near these double doors, because there's a tripline — see here? — a foot off the floor. We don't know what it does, but let's not mess with it."
Horpt shyly rejoins the group, flapping down to land on Sigbert's shoulder. Sigbert explains the little winged man's presence to the newcomers, and Esma interjects that it can't be trusted — "It's "Master" is out there somewhere, and as soon as that Master shows up, this evil thing will surely betray us!"
Shifting attention from that tense exchange, everyone agrees that the bent portcullis must be a sign of the bull lord's passing. The wooden bridge looks in rough shape, worn, weathered, and rotten with the passage of time, but it's the only way out of the tower besides back down into the thornling warrens. A plan is concocted to pass safely across the bridge.
One end of the silk rope is tied around Horpt's waist, and he flies out through the double doors, above the bridge, as Sigbert plays out the rope behind him. Suddenly, a great shadow passes over the homonculus, and everyone looks up to see the silhouette of the great eagle against the sun. Horpt hurries along to the other side, either unnoticed by or beneath the attention of the giant bird of prey.
Horpt passes through the portcullis, around one of it's vertical iron bars, and flies back across the bridge. The tail end of the silk rope has been tied to the hemp rope, so as the PCs reel in the silk, it is replaced by the stronger hemp. Soon, they have a double rope line stretched between the portcullis and one door of the tower they occupy, where it is firmly secured. Horpt reports that there is a heap of rope piled up just on the other side of the bridge, blocked from view by the arc of the bridge itself.
Gareth is the first to cross, using the hemp rope for stability, and trailing the silk rope, which is tied in a harness about his torso. I ask him to make a Luck check to see if the bridge holds, and he fails; a plank gives way beneath him. Given their safety precautions, I've conceived of the bridge crossing in three steps: Luck check to see if part of the bridge collapses underfoot, then a DC 10 Reflex save to keep a hold on the guyline, then a DC 15 Reflex save to keep from smashing back into the base of the tower (and taking 1D6 damage) when the safety line swings back. Gareth makes the DC 10 Reflex save, keeps his grip on the guyline, and makes his way across to the other side.
He examines the heap of rope that Horpt mentioned and sees that it is really thick, about twice as thick as the party's hemp rope. He starts to unwind it, figuring it will make an even stronger guyline, and discovers that it's actually a rope ladder, secured to an iron ring set into a flagstone. Interesting. He and Sigbert discuss this discovery across the windy gap, and they revise their plan. After 10 minutes of tying, untying, pulling, and retying, they've replaced the double line of hemp rope with the rope ladder, hoping it will somehow provide a safer crossing.
To make things go faster, and taking into account their attention to detail for this obstacle, I now tell them that each PC just needs to make a DC 5 AGI roll to cross the chasm safely using the rope ladder and safety harness. Everyone makes their roll except Daisy, who slips but recovers, and Oswald, who has the heaviest and most unwieldy load (his big sack, slung across his back and secured with some jury-rigged strapping, full of firewood and the chest containing the pewter-bound "book"). He recovers also, but I rule that the sack slips off his shoulder and hits the bridge, the last blow that it can sustain. The remains of the bridge collapse into the chasm as Oswald clings frantically to the rope ladder, his sack now hanging beneath him. Struggling against this weight, he makes it to the far side without losing any belongings. All told, this cautious crossing has taken up a little over an hour of in-game time.
After catching his breath, Oswald decides to check the floor of the gatehouse entry for good measure, He unburdens himself of his heavy sack, and pulls out a couple of hefty pieces of firewood. Then, he starts tossing the firewood through the portcullis onto the floor beyond, in order to test for traps. Gareth, realizing what Oswald is doing, and seeking to avoid any potentially dangerous results of such reckless behavior, moves quickly out from under the cover of the gatehouse entry.
One of the pieces of firewood hits a pressure plate disguised as a flagstone, and a rust-colored mist issues with a hiss from some hidden outlet into the entry hall, filling the space between the portcullis and the courtyard. Gareth was smart. The PCs can only speculate about the properties of this gas as they wait for it to settle and disperse, but I know that it was created from the glands of the rust monster they found dissected in the totem cave, and that it could have destroyed any metal on the person of anyone caught within.
The trail of blood leads up to the main entrance to the citadel, which draws their attention immediately: the door is a great stone disc, some 12' tall, encircled by a line of solid brass that, in striking contrast to the rest of their surroundings, could have been polished that morning. Carved into the door are six pictograms, depicting six animals: dragon, lion, horse, hawk, snake, spider. Gareth immediately recognizes these symbols as matching those on the golden scepter he found in the totem cave.
But before the adventurers attempt to breach this door, they spend some time checking out the courtyard and towers. Sigbert dispatches Horpt to the top of the north tower, and he returns quickly to report that the tower is open at the top, "full of webs," and that "something lives there." He doesn't know what, but he saw movement in the darkness that caused him to flee. The party moves close enough to see that the ground-level entrance is an intact wooden door, framed by a stone carving of a spider presiding over three webbed victims. No one wants to investigate further.
The south tower is similarly open at the top, its interior floors having collapsed, and is full of branches, debris, and in some cases what look like entire dead trees. Its agreed that this is probably the nest of the giant eagle, and should not be disturbed. Scanning the skies anxiously for sign of the great bird, they return their attention to the disc-shaped portal.
Gareth considers ways in which the door might be opened, and suggests that perhaps the symbols must be touched with the scepter in a particular order. He's too short to reach any of them, however, so he hands the scepter to Sigbert, and asks him to touch the horse symbol with it. Sigbert obliges, and with a shuddering rumble the disc separates down the middle into two half-circles, each of which rolls out of sight into a recess in the citadel wall. Easier than expected!
The party peers into the darkness beyond.