Grab the key

You decide to take your chances out there and make a grab for the key. There's no guarantee that you would be safe in the cell, and at least outside you have a chance to get free.

Lifting the flap up from the food tray slot, you stick your arm through and attempt to grab the keys off the fallen guard. The blood makes the keys slick and slippery, and they fall from your grip several times. But eventually you get a firm grasp of the ring and yank it off his belt.

It takes a few more moments after that to find the right key. When you finally hear a satisfying click and your celldoor swings open, your heart soars.

As you step out of the cell, you briefly consider taking the guard's armor and sword, which is belted to his side. You would certainly feel safer with those on you. Looking at the armor though, it seems to be worn with a number of buckles and complicated straps. You doubt you would have enough time to remove it off the guard and then put it back on your body. Furthermore it would slow you down, and right now running away is more important. Also, you realize that you have no idea how to use a sword, and you'll just as likely hurt yourself with it. Not to mention the weight issues again. Speed and agility are the only tools that you need right now.

You break into a sprint, trying to retrace the path the guards led you through. First a left, then a right, then a left again. Up some stairs, down some more. All around you, you can hear the sounds of fighting, just as loud as before, but you've yet to see a soul.

Finally rounding a corner, you come to an intersection, each with equally unappealing circumstances. Stopping to catch your breath, you pause to survey the situation.

The stairs to your left look like they lead to a guard station. Considering the battle raging on the surface, you don't think that it's likely there are any guards in there, but at the same time, they could be using it as a temporary headquarters. Or worse, the attackers could have already made it that far. Indeed, you think you heard someone moving around up there.

To your right is an inclined slope also heading upwards. The battle sounds much more violent and much closer up there. You can only assume that you'll be running straight into a melee if you go that way, but that might also be your best chance. With all the chaos and confusion you might be able to slip through.

Or you can always return back to your cell. No one has noticed you yet, and maybe it would be safer after all.