The army in question could be traveling through the underdark, emerging from caves near their intended targets.

A great enchantment creates a field of invisibility, preventing anyone from outside the field seeing the army within it.

Or perhaps the army marches through a parallel plane, opens portals in the middle of their intended target, and overwhelms them from within.

Along the way, the PCs meet up with some German scientists with their own military escort who are bound for the same site. The commander of the US troops decides that it’s in their best interests to work with the Germans, and so the two groups go together to investigate.

When the source of the mysterious radio signals is finally located, it’s discovered to be an alien craft hidden in the heart of a pyramid. The following day, while the scientists are investigating it, the Germans betray the Americans and kill all of the troops. One of the soldiers manages to warn the PCs, but they’re now on their own and must make sure the technology doesn’t fall into German hands, not to mention escape with no military or survival training!

Approaching the PCs, the man steps down from his horse and nearly falls over, but catches himself on the stirrup. He produces a thin package from his pocket. “Please,” he says, “you must get this to the city.”

If the PCs question him, he will say only that “they” will not be far behind and the PCs must hurry, for “it” cannot fall into “their” hands. When he’s convinced the PCs to do this task for him, the man takes a signet ring off his finger with a symbol of a hammer over a shield, telling them to bring that along with his package to Malleus Hall and find Gregor Teuber.

At some point, perhaps midsentence, the soldier falls to the ground. His burden transferred, he’s finally allowed himself the peace of death.

He’s begun bolstering his army, and on top of that has decided to complete and re-man the fort at Weston Hill. It’s been standing derelict for the better part of a century, though, and the first thing the king decided should be done is to assess the current situation. At the moment, his army is occupied with recruitment and restructuring efforts, so the king must hire adventurers to go and explore the fort. Of course, he ends up hiring the PCs.

The situation at the fort is relatively benign. It is somewhat difficult to enter; the portcullises are long-since rusted shut and the stone walls are as impassable as they were designed to be. However, it should be fairly simple for a well-prepared group to gain entrance.

Most of the buildings have been destroyed by time and the elements. The barracks and tower still stand, though. Exploring the barracks, the PCs will eventually come to a wall in the basement which appears hastily-erected. If they examine it, they find it to be hollow and, behind it, is a door.

The door has been barred and locked, the lock melted with acid, spikes of metal have been used to jam the door shut, and mortar was used to seal it. Clearly, some effort was made to ensure that this door should never be opened, from one side or the other.

Inside are several dozen dessicated corpses, the remains of the supposed mutineers. Several of them are missing chunks of flesh, and teeth marks can be seen on the bones. One corpse remains notably intact, and is wearing finer garments than the rest. It was the commander, and in his hands he holds a journal detailing what really happened.

A few weeks after they’d first settled into the fort, one of the soldiers fell ill, complaining that he was seeing and hearing things. Hours later, he turned hostile, savagely attacking the doctor. He was locked in the brig. A few days later, the same fate befell another soldier and another, and within a week all but a few of them were locked away in this room. Finally, when the commander himself started seeing things, he ordered his second-in-command to lock him in with the rest and leave the fort, and to convince the king to abandon it.

If the PCs tell Thornwald what happened, he dismisses it and orders the fort re-staffed. He also hires the PCs on as scouts, to explore the land around the fort. He charges an experienced man by the name of Sir Andromus Galwain to command the fort.

A few weeks after the fort is re-opened, Sir Galwain sends for an audience with the PCs. He explains to them that the same events which happened when the fort was first opened are happening again; he’s sent word to Thornwald, but suspects the king will not allow the fort to be abandoned. Galwain doesn’t want to put his own men into investigating what’s happening, for fear of what the truth of what happened so many years ago might do to morale, and so he asks the PCs to figure out what’s causing this sickness and fix it.

The fort was almost completed. In fact, the only construction left to be done was in the tower crowning the barracks, and even that was mostly completed. The fort consists of the aforementioned barracks, a smithy, stables, church, mess hall and kitchen, all surrounded by a tall wall with a single entrance. Twin portcullises block the entrance.

The reason the fort was abandoned is a matter of some speculation. The official story is that the commander was a traitor to the crown and wanted to claim the fort as his own dominion. The man’s second in command, the nephew of the king, successfully lead a mutiny against the commander and his men. In the end, only seven people survived, including the smith and the king’s nephew. He convinced the king that it was a fool’s errand to waste any more resources on the fort, and that’s the end of that.

Most of the survivors disappeared or died under mysterious circumstances in the following months. Some claim that it was a curse, other’s say it was the king’s nephew trying to cover up what really happened.

Encounters with The Fort at Weston Hill

A smith, claiming to be the grandson of the smith who survived the Weston Hill Mutiny, tells the PCs of stories his father told him; a crate of a rare, and potent, metal abandoned when they left. If the PCs will retrieve the metal for him, the smith can make them weapons of the most exquisite quality.

Some teenagers on the train, seeing the American man and thinking he looked like he’d have some valuables on him, mugged the spy and ran off. They escaped with his briefcase and his suitcase. They were unable to open the briefcase, which contained the biological weapon as well as the spy’s collected intelligence, but in the suitcase they found the prototype weapon.

Looking to make a quick buck, they sold all the stuff to a man named Alexei Bobylev. Alexei used the weapon to kill some personal enemies in the Russian mafia. The gun leaves no traces, it’s as if the victim died of a heart attack. The only thing suspect about the deaths is that they all happened so closely together and only two of the dead men were in poor enough health to be at real risk of a heart attack.

And this is where the PCs come in. They’ve been sent in by the American government to recover the spy’s belongings, and keep it quiet. Unfortunately, the string of bizarre deaths made the national media, and now everyone’s swarming over the area. The PCs will have to contend with the following:

The mafia: They strongly suspect Alexei is behind the murders and are looking to exact their revenge.

The Russian government: The PCs have to recover the items before the Russians do; the spy had also gathered some intelligence on Russia itself, and it lead to an international incident if they found out the US was spying on them. Needless to say, the use of force in dealing with the Russian agents is not an option.

The terrorist cell: They recognized the cause of the deaths and immediately guessed that their stolen technology would be found there. They’ve sent men to recover it.

Time: Immediately after committing the murders, Alexei went into hiding. Since then, he’s been trying to bust open the briefcase, and his less-than-gentle means could spell disaster if he breaks the seal on any of the vials inside.