Just about to have an awesome end to a campaign. Pardon me if I go on a bit...
The heroes are helping to stem an Orcish invasion of the Wild Coast. They sneak into the Orc city (basically a series of interconnected buildings with a fort at one end all built on an ancient tel) to scout numbers and try to discover plans. Unfortunately they were betrayed by (an ex-PC) paladin of Hextor. They get dropped into a death trap and are left to die. Of course they don't. They kill the giant scorpions and escape into the ancient labyrinth beneath the city.
Aside: While down there fighting the occasional animated statue they discover there is a ghoul city in the caverns beneath the labyrinth. A great magical seal is keeping the ghouls from coming up. I assumed they would destroy the seal and let the ghouls finish off the Orc city. ANd they certainly considered it. And may even intend to go back to do it, if they live.
They find a way out of the labyrinth into the Orc slave pits. From there they break into the city proper. They capture a couple of guards. Kill them outright, no attempt at interrogation or forcing them to act as guides to get them out of the warren of an ORc city. So they start wandering at random through the city. Next they capture a couple of ORc children who are apprenticed to a weaponsmith. They interrogate them enough to discover that just down the corridor is half a dozen Orc weaponsmiths. Kill the kids and wait. Weaponsmith comes down to see what the lazy slugs are doing. PC's hit him, enough that he goes down but not enough that he dies outright. He starts screaming. PCs charge smithy. A few smiths stay and fight, a couple run to raise the alarm.
So now our heroes are in an Orc city with the alarm raised. They start running at random. A few rooms go by and they run into their first armed Orcs. Fighting. Orcs screaming they've found the filthy humies, reinforcements come running. They beat of the first wave of attackers and decide to go up to the series of interlocked roofs that cover the entire city. Nothing much stopping them running for the edges and trying to escape into the forest. Nothing except their own stupidity. The group leader orders them to charge the castle at the far end of the city.
Remember this is a fort on high alert, the alarms are still going off. Guards are on the walls. So they make it across the roof tops to the fortress wall, all strung out as a few folks have failed the various jump checks to go from level to level. A few more orcs have reached the roof and are charging them. ORcs on the fort walls are shooting at them. At this point the party leader says 'I have no idea how we're going to get through the walls.' Thinks a moment then 'back down below!' So now they've gone back into a room. ORcs are on the roof above them, yelling out their position. The main fort is right next to them. The defence is getting organised.
ANd that's where we had to leave it for the session. The group is mostly out of healing now. All the members are at least a little injured. The one PC who's likely to survive is the rogue who, the moment they were on the roof, said 'I dive into the shadows!' And there he has stayed. Smart rogue.
The others will sell their lives dearly I'm sure. I've been keeping track, they've killed 26 orcs and 2 bugbears in this running battle so far. They have some powerful summoning spells they picked up in the labyrinth. One of them summons a giant fiendish land octopus.

So the fight is far from over. But with over a thousand ORcish soldiers around them, not to mention the higher level commanders, I don't see them escaping. They may well prove me wrong but had better start displaying more smarts than they have recently.