This is a game. Tell the character to do something, such as 'look through window'. When speaking, you can create new information, and it will be treated as true. If you wish to give a game character false information, include the text '[lie]' after the speech. Between narrative posts, the first sensible command will be taken. All non-command text should be made clear that it is as such (italics probably not necessary).

You wake up in a warm, dark room. There is a small slit window - you are in a relatively comfortable prison cell in a castle of the enemy. You can tell from the light cutting through the darkness that it is near dawn, and the fire in the north side of your room has all but gone out - a few embers remain. You're laying on a mat of straw covered with a simple brown fleece, roughly in the middle of the room. The only feature of the south wall is a latrine. The west wall has a door made of iron bars, and you can see the guard on a chair next to the door on the outside, possibly asleep.

You are imprisoned for attempted treason. There is a general unrest among the people with the current monarch; his taxes are too high and his compassion is too low. He is greedy for war. Your mission failed due to an unknown informant betraying your plan to the king's guard. You have been imprisoned for two weeks today. There is talk of a public hanging any day now, after you and other prisoners have been fully interrogated for useful information to capture other conspirators. You had three contacts, and have given over no information to the guard yet, true or false.

You check your inventory. You have:
Peasant's robe [equipped]
Small rope [equipped as belt]

The guard will probably wake soon. What would you like to do?
Contemplating her next move, sassy conspirator Shaniqua Freeman thinks she can outwit the guard into letting her go if she gives him fake information.

Mmm MMm, suga'. I check how much I can see out this skinny-ass winda' while I wait fo' Snores McSleepy to wake up. Ain't nobody got time fo' that.
Your name is Shaniqua Freeman. You have a SASSY nature.

You look outside the window. It is clear that the castle is on a hill near the a sea; you know it must be the Mediterranean. You can see the sea on your right, the south. Red terraced buildings form a village around the castle, and a church spire can be made out in the mid-distance. You can hear birds, but the village is still quiet as it's only just daybreak.
Try using the straws to stoke the flame. The fire might come in handy later somehow.
Burn off your fingerprints with the fire.
You unpack a handful of straw from your bed, and restoke the fire with little trouble - however there is no fresh wood to burn, so the fire will die within a few minutes.

Fingerprints were not used for forensic identification until the late 19th century, and castles were not used as prisons or fortresses beyond the 16th century. A straw fire is also not hot enough to burn off fingerprints. Are you sure you want to put your hands in fire?
Try and figure out what else you can burn, maybe the fleece or part of your robe.
Size up the guard
The fleece seems flammable, as does the straw beneath it. The top side of the latrine has stone sides and a flat oak top with a hole in it. The oak is about two fingers in width, so it would only burn with a very hot fire.

The guard is a strong looking man with a slight paunch. He is wearing chainmail covered with simple cloth. He probably has a weapon, but it is not visible from his left side.
Use fleece and rest of straw to help the fire burn hotter, then put the oak top in the fire.
The oak top is encased in the stone sides, you can't move it.
Thoroughly search around room for anything that can be of use. A rock, some twine, a stick, a key. You know, everyday prison cell litter.
You search around the room. You find some soft rock that could be used for writing. A couple of the floor stones (perhaps the size of a brick) are loose.

Added to inventory:
Chalk rock [equipped in right hand]
MmmHMm. You know you gotta check to see if you can pull a couple of those stones out, baby.
Retrieve a stone from the floor, write out a message crying for help, and throw it out the window towards some random house. I'm sure someone will read the brick that came crashing through their ceiling, and come rescue us.
Lure the Guard over with your sassy nature and smash his head with the rock when he opens the cell gate and gets close.
(I assume the character is female, otherwise hope and pray the guard is gay)
Sorry for taking so long to respond guys, it's been a really busy few days.

You can pull out some of the stones without making much noise. There isn't really space on the stones to write anything beyond a couple letters (your chalk rock is not a fine-tuned instrument...) so instead, you decide to give the guard an early wake up call.

"Hey suga', you got a lady? Cus you should with a body like that, mMm."

Let's do some conversation. See if you can get the guard to stand close enough to the door to take a swing at him. You're holding a cobbled rock behind your back, and the chalk rock is in a near corner.
You throw the rock at him. He wasn't very close to you, and manages to dodge the missile in time. He yells something unintelligible and runs away, presumably to get another guard. WHAT NOW