The party of adventurers take up a quest to kill a small tribe of goblins at an encampment on the edge of the forest near the town of Gullsvale. Of course, goblins are no match for the hardened adventurers which the PC’s will probably be.
Before they leave the town, they equip themselves, of course. One particular trader has a most exsquisite sword on display, and the price? The price is as cheap as a worn dagger would be! This sword has a small crest of an eagles wings imprinted on the hilt - which is golden, and inlaid with gems and baubles. The blade looks brand new, and is almost certainly enchanted. Who could refuse such an offer? So the warrior in the party buys it, and it is forgotten for the majority of the goblin hunting.
After several days of travelling and fighting a pack of disorganised, frail goblins, the party begins to head back with the head of the goblin leader for proof. On the way back, they make to pass a patrol of guards. The guards, however, stop the small party. “You are accused of regicide. The penalty is death.”
The surprised party must now fight for their lives against a pack of trained guards - far more disciplined than a small pack of goblins. Once they kill the guards they must find out what is going on.
Should they ask the right people, and be smart about it, they can find out, without giving themselves away, that the king of the area they are in had gone missing a few weeks ago when he was out hunting in the forest. Many witnesses had seen the warrior of your party carrying the royal sword of the king, the eagle-wing symbol of royalty stamped on the hilt for proof. The warrior and the rest of the group has been described in detail, along with the accomplices - the rest in the group. Now, they have the entire kings garrison looking for them, along with other adventurers and freelancers looking to make a hefty profit by collecting the bounty on their heads.
What must the players do? They can’t explain their ways out of it (“Yeah right, they ALL say they were framed. Get ‘em, boys!”) They must go back to the town, without being seen, and find the original trader to get the story. Either the trader killed the king, so they could just get him to confess somehow (How do you get a man to admit they killed a king, when the penalty is death?), or perhaps the trader bought the sword off someone else, or found it in the forest? If so, the sword must be traced back to the first place.
If the sword was traced to a particular spot in the forest? What if the king is trapped or held captive in the forest by some evil creatures? The adventurers have no choice but to find the king and save him, or they will be hunted for the rest of their lives.
If they DO save him, however, what originally was a death penalty, may be respect, rewards and even lordship.
One thing to remember, however - even if they DO clear their names in the end, the more guards and innocents they kill trying to save their own skin, will lower their respect substantially. They may not be wanted anywhere. So they have to be smart about it. Travel at night, use stealth throughout the towns. It would be a good way to teach a bumbling warrior how to travel silently.
Note: things can be changed to fit this plot with different characters. Don’t have a warrior? The heirloom is a mages staff, or a brilliant bow, or just an intricate amulet. Something cheap, yet brilliant, which will entice the adventurers into buying it.