# How to escape a room using a dead demon



## Rickswan (Nov 25, 2015)

So here's the setup: a group of characters are trapped behind a metal door in a subway. There is a dead demon in the room that they killed with firearms. I'm trying to come up with the physiology of said demon. I've decided that part of its physical makeup will be sulfur (brimstone = sulfur). I'm thinking they could use the demon's physiology to escape the room. 

It is your traditional fireball throwing red horned demon. Perhaps they have a gland that secretes some sulfur-based contact explosive in order to create the fireballs, or something that allows them to spit sulfuric acid. Perhaps they can manifest a thermite-like compound that could melt through metal. I don't know enough about chemistry to really know what is possible; I have no idea realistically how long it would take for sulfuric acid to dissolve enough of a door or metal bars in order for one to make an exit. 

So, what do you think would be most feasible, in a hard sci-fi sense? Obviously demons would have a magical element to them - perhaps they could synthesize volatile chemicals at a faster rate than physics would allow, and perhaps their body parts can go on living after their vital parts are destroyed - but you know, as realistic as reasonable.


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## Cran (Nov 26, 2015)

You want a MacGyver? OK. 

The firearms are standard? So, you can break down some bullets for the propellant primer powder; more likely than having a strip of magnesium on hand, right? 

The metal door, or better, the hinges and/or lock are iron-based? Neglected? A bit rusty? Excellent. 

Does one of characters smoke cigarettes? Chew gum? Bring a packed lunch? No? OK, how about the room - any pipes or panels that look like they are made of aluminium (aluminum)? Is there a toolbox or toolkit handy? 

You want a metal file or some high-grade abrasive to remove the thin oxide layer and then collect as fine as possible 1 part aluminium for every three parts of iron rust powder you can put in one place (lock or hinges). Add the black powder. Make a wick - a strip of paper, cloth thread - easy. 

For added oomph, and some really cool black poisonous fumes and a lumpy  mass of black solid foam: sure, extract the sulphur (sulfur) from the  dead demon and add it to the mix.

Ignite. 

After you have recovered your eyesight, and treated the character who lit the mixture for burns, (and if you did the sulfur bit, coughed up your breakfast) check to see if the molten iron has done the job. If not, take a deep breath and repeat.


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## Rickswan (Nov 26, 2015)

Ah, excellent, somebody who knows chemistry! May I have some clarifications? 


Cran said:


> You want a MacGyver? OK.
> 
> The firearms are standard? So, you can break down some bullets for the propellant primer powder; more likely than having a strip of magnesium on hand, right?


Okay, so more info about the scene: I'm imagining the area they're in looks a bit like [this]. The turnstiles and door itself are either welded shut or blocked off by rubble. Maybe they're low on ammo and can't just shoot their way through (actually, without a breaching shotgun I'm not even sure that would be possible - ShootOutTheLock). The trapped characters are varied - there's an FBI Bomb Defusal expert (probably the one figuring out the bomb), some SWAT guys (bullets), a biologist (figures out how the different demons function which helps the team out), etc. At some point the biologist observes that the demons chuck fireballs as projectile weapons. This would mean they are able to somehow extremely quickly synthesize a contact explosive (Picric acid? Flash powder? Something similar to nitroglycerin?) inside a flaming shell - like a biological/magical molotov cocktail. 

So sure they can break down their remaining bullets... but what would be the purpose of keeping a magnesium strip on hand? Other than Deus Ex Machina? 


Cran said:


> The metal door, or better, the hinges and/or lock are iron-based? Neglected? A bit rusty? Excellent.
> 
> Does one of characters smoke cigarettes? Chew gum? Bring a packed lunch? No? OK, how about the room - any pipes or panels that look like they are made of aluminium (aluminum)? Is there a toolbox or toolkit handy?


Sure! The door/iron bars around the door are possibly rusty. This is part of why I considered sulfuric acid - I know it could dissolve the metal, the question is how long would it take. So anyway lets say that sure, somebody smokes cigarettes (or the demon could produce fire somehow). Sure, there is a source of aluminum and somebody probably has a toolkit. 



Cran said:


> You want a metal file or some high-grade abrasive to remove the thin oxide layer and then collect as fine as possible 1 part aluminium for every three parts of iron rust powder you can put in one place (lock or hinges). Add the black powder. Make a wick - a strip of paper, cloth thread - easy.


Bomb defusal guy could have a file - so you're saying he's filing fine dust off the aluminium object, and sprinkling it in with dust filed off of some rusty iron object? This makes the main charge? 



Cran said:


> For added oomph, and some really cool black poisonous fumes and a lumpy  mass of black solid foam: sure, extract the sulphur (sulfur) from the  dead demon and add it to the mix.
> 
> Ignite.


So sulfur would add oomph to the explosion? 



Cran said:


> After you have recovered your eyesight, and treated the character who lit the mixture for burns, (and if you did the sulfur bit, coughed up your breakfast) check to see if the molten iron has done the job. If not, take a deep breath and repeat.


 So to summarize our working idea here: 
(1) They have access to propellant primer powder, possibly through broken down bullets. 
(2) They have a magnesium strip (but why would they have one?) 
(3) Someone is able to file off the "thin oxide layer and then collect as fine as possible 1 part aluminium for every three parts of iron rust powder you can put in one place (lock or hinges)" 
(4) They add the black powder (from the bullets), presumably the magnesium, and the sulfur. Somehow they keep this dust mixture contained to one spot (the hinges or lock). 
(5) They ignite the mixture with a wick.
(6) There's a modest explosion, followed by a bit of molten iron? 

I like it. It's going somewhere. Maybe the demon's physiology could be utilized a little more, perhaps for ingredients, but I definitely like where this is going.


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## Cran (Nov 26, 2015)

Rickswan said:


> Ah, excellent, somebody who knows chemistry! May I have some clarifications?
> Okay, so more info about the scene: I'm imagining the area they're in looks a bit like [this]. The turnstiles and door itself are either welded shut or blocked off by rubble. Maybe they're low on ammo and can't just shoot their way through (actually, without a breaching shotgun I'm not even sure that would be possible - ShootOutTheLock).


What I know about chemistry is limited to early university (Chem 101) and mostly forgotten. I was imagining them in a utility room or service tunnels with a solid door or two. If the space and barrier is like that in the image, why don't they just climb over? A lot less fuss and even easier if the turnstiles are welded or blocked tight, and there is plenty of rubble lying around.



> The trapped characters are varied - there's an FBI Bomb Defusal expert (probably the one figuring out the bomb), some SWAT guys (bullets), a biologist (figures out how the different demons function which helps the team out), etc. At some point the biologist observes that the demons chuck fireballs as projectile weapons. This would mean they are able to somehow extremely quickly synthesize a contact explosive (Picric acid? Flash powder? Something similar to nitroglycerin?) inside a flaming shell - like a biological/magical molotov cocktail.


Well, the biologist might have some picric acid on hand (for chemical testing), and the SWAT guys might have some flash-bangs, so yes, you could go that route.




> So sure they can break down their remaining bullets... but what would be the purpose of keeping a magnesium strip on hand? Other than Deus Ex Machina?


Exactly; that's why I suggested the primer powder from a bullet (would only need one per thermite charge) is much more likely than one of them just happening to have a magnesium strip on hand.




> Sure! The door/iron bars around the door are possibly rusty. This is part of why I considered sulfuric acid - I know it could dissolve the metal, the question is how long would it take. So anyway lets say that sure, somebody smokes cigarettes (or the demon could produce fire somehow). Sure, there is a source of aluminum and somebody probably has a toolkit.


The reason for the cigarettes/smoker or chewing gum or packed lunch was for the aluminium foil in the pack or gum wrapping; much easier to tear or cut a sheet of aluminium foil (in the process, exposing unoxidised aluminium, although it would be better to abrade the foil sheet first; the more oxide layer removed, the better) than to spend an hour filing off enough aluminium dust from some item in the room. 

A handy standard toolkit left or dropped by a subway service person or a tradesperson (plumber, sparky, mechanic) will almost certainly include a metal file, and probably one or two other useful things (gaffer (duct) tape for simple temporary repairs, or a wire brush for removing loose material like rust, for instance). 




> Bomb defusal guy could have a file - so you're saying he's filing fine dust off the aluminium object, and sprinkling it in with dust filed off of some rusty iron object? This makes the main charge?
> 
> So sulfur would add oomph to the explosion?


There shouldn't be any explosion. If there is, it's because whoever set the charge added some biological material, steam, or pressure container. If there are any pyrotechnics, it is due to contaminants (like spit, sweat, or the poor guy's finger). Pure iron is fairly soft and malleable, and when molten, which is what you get from the aluminium+rust+primer reaction, will nicely  burn a hole in a metal lock or bolt with a similar melting point or soften  hinges enough to tear away.

Adding sulfur provides a second exothermic reaction - added oomph - converting the hot molten iron to iron sulfide, which can be counterproductive, as it hardens the bits you've just melted into a tougher alloy. Add sulfur and heat to iron and you have steel; the more sulfur, the harder and more brittle the alloy. In air, the reaction will also produce iron sulfide foam, a magnificent space-filler, and a particularly smelly black smoke. You won't make any friends for the one who makes that batch.





> So to summarize our working idea here:
> (1) They have access to propellant primer powder, possibly through broken down bullets.
> (2) They have a magnesium strip (but why would they have one?)
> (3) Someone is able to file off the "thin oxide layer and then collect as fine as possible 1 part aluminium for every three parts of iron rust powder you can put in one place (lock or hinges)"
> ...


(1) Just one bullet per mix will do. The powder is the igniter for the thermite reaction.
(2) You would only need a magnesium strip if you have run out of bullets. Magnesium is an alternative igniter that burns very easily and hot enough to properly initiate the aluminium+iron oxide (rust) exothermic reaction.
(3) Only needed if you don't have any aluminium foil on hand - powder is better, easier to make a good mix, but foil netting (make lots of holes) or fine strips or pieces can work.
(4)Yes, although you only need the powder; the others are optional and not ideal. A paper cone would do to pour the mix into a lock if old-fashioned, and would provide the wick. If the lock is modern, then a paste would be better, although that would make it explosive - stand well back. Another way is to put the dry mixture into a small open container - a cigarette packet, or one of the biologist's specimen jars, and duct tape it to the target or tack it with chewing gum.
(5) Yes, you need enough heat or flame to ignite the primary igniter which will then burn hot enough to start the main reaction.
(6) There should be a concentration of a lot (a lot!) of heat, which converts the powdered rust into molten iron. If there is an explosion, it is due to contaminants in the mix, like moisture (steam expansion) or biological matter (ditto), or containment pressure. The radiant heat would like that of a modest kiln.


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## Rickswan (Nov 26, 2015)

Cran said:


> What I know about chemistry is limited to early university (Chem 101) and mostly forgotten. I was imagining them in a utility room or service tunnels with a solid door or two. If the space and barrier is like that in the image, why don't they just climb over? A lot less fuss and even easier if the turnstiles are welded or blocked tight, and there is plenty of rubble lying around.


You know what, I like that better. Here is the reason I chose subway tunnels: I have a big group of characters who don't know each other, some are civilians and others are law enforcement. They need a valid reason to come together and work as a team. I figured since it takes place in NYC, what better place than the subway? So I'm totally fine with the locale being moved to a utility room or service tunnels. If it's a service tunnel, there could be debris from a wrecked train or some collapsed ceiling from a fight that ensued. A utility room or some such would also have the added benefit of further explaining why they don't try to shoot the lock: they try to shoot it, it doesn't work, and it ricochets around the room to the chagrin of those in it. 



Cran said:


> Well, the biologist might have some picric acid on hand (for chemical testing), and the SWAT guys might have some flash-bangs, so yes, you could go that route.


Assuming they had picric acid and flashbangs, what could they do with those? I am intrigued. 



Cran said:


> Exactly; that's why I suggested the primer powder from a bullet (would only need one per thermite charge) is much more likely than one of them just happening to have a magnesium strip on hand.


So they're creating a thermite charge (aluminum-iron(III) oxide), nice. To quote Wikipedia: "Thermites have diverse compositions. Fuels include aluminium, magnesium, titanium, zinc, silicon, and boron. Aluminium is common because of its high boiling point and low cost. Oxidizers include bismuth(III) oxide, boron(III) oxide, silicon(IV) oxide, chromium(III) oxide, manganese(IV) oxide, iron(III) oxide, iron(II,III) oxide, copper(II) oxide, and lead(II,IV) oxide.[1]"



Cran said:


> The reason for the cigarettes/smoker or chewing gum or packed lunch was for the aluminium foil in the pack or gum wrapping; much easier to tear or cut a sheet of aluminium foil (in the process, exposing unoxidised aluminium, although it would be better to abrade the foil sheet first; the more oxide layer removed, the better) than to spend an hour filing off enough aluminium dust from some item in the room.
> 
> A handy standard toolkit left or dropped by a subway service person or a tradesperson (plumber, sparky, mechanic) will almost certainly include a metal file, and probably one or two other useful things (gaffer (duct) tape for simple temporary repairs, or a wire brush for removing loose material like rust, for instance).
> 
> There shouldn't be any explosion. If there is, it's because whoever set the charge added some biological material, steam, or pressure container. If there are any pyrotechnics, it is due to contaminants (like spit, sweat, or the poor guy's finger). Pure iron is fairly soft and malleable, and when molten, which is what you get from the aluminium+rust+primer reaction, will nicely  burn a hole in a metal lock or bolt with a similar melting point or soften  hinges enough to tear away.


So it really is more of an exothermic thermite reaction thing - exothermic reduction-oxidation (redox) reaction, as Wikipedia calls it - to melt, rather than explode or dissolve through the door. 



Cran said:


> Adding sulfur provides a second exothermic reaction - added oomph - converting the hot molten iron to iron sulfide, which can be counterproductive, as it hardens the bits you've just melted into a tougher alloy. Add sulfur and heat to iron and you have steel; the more sulfur, the harder and more brittle the alloy. In air, the reaction will also produce iron sulfide foam, a magnificent space-filler, and a particularly smelly black smoke. You won't make any friends for the one who makes that batch.


So adding sulfur would be a bad idea. 



Cran said:


> (1) Just one bullet per mix will do. The powder is the igniter for the thermite reaction.
> (2) You would only need a magnesium strip if you have run out of bullets. Magnesium is an alternative igniter that burns very easily and hot enough to properly initiate the aluminium+iron oxide (rust) exothermic reaction.
> (3) Only needed if you don't have any aluminium foil on hand - powder is better, easier to make a good mix, but foil netting (make lots of holes) or fine strips or pieces can work.
> (4)Yes, although you only need the powder; the others are optional and not ideal. A paper cone would do to pour the mix into a lock if old-fashioned, and would provide the wick. If the lock is modern, then a paste would be better, although that would make it explosive - stand well back. Another way is to put the dry mixture into a small open container - a cigarette packet, or one of the biologist's specimen jars, and duct tape it to the target or tack it with chewing gum.
> ...


(1) Understood. 
(2) Now I get it. Nobody has a magnesium strip just lying around so they use the primer powder from a bullet. 
(3) So the aluminium foil from a pack of cigarettes, gum, or shavings from something made of aluminium is added to some dust shavings of rust to create the thermite charge. Would foil from cigarettes/gum create a big enough charge, though? 
(4) How would one make the rust/aluminium mixture into a paste to make it explosive? Would it explode via a fuse, or by percussive force (possibly a bullet) - ? The closest I could find to such a thing was [this]thread, which doesn't have a lot of answers. If they went with the dry mixture in a container method and taped it to the lock/hinges, the trick would be to keep the fuel above the lock/hinge without it just dropping to the ground. 
(5) Easy enough. 
(6) Thermite burns through the lock or hinges. They may have to try a few times, but this sounds legit. I like it!


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