actually from a narrative perspective 'it's in a volcano' is pretty airtight
the volcano is erupting but nobody can find a way out, and all the tools to escape the prison are in reach in the prisoners, so the guards are going nuts and have gone totally murder-happy because the lava's rising and it's hitting the lower parts of the jail first and some are trying to keep order but others are just forgetin shooting everyone they can because hoLY stuff, the VOLCANO is forgetIN ERUPTING
but then in all this chaos the prisoners also have to escape because tHE VOLCANO IS forgetIN ERUPTING and they can use the chaos to their advantage grabbing things off of dead guards or waiting for lava to hit important power generators so they can break into areas that only open after a certain amount of time has passed
and ultimately the goal of both sides is to escape the volcano before it forgetIN ERUPTS but wheras the prisoners don't have weapons the guards don't have tools and you obviously can't work together so both teams have to sabotage one another (and possibly eachother within the same team) in order to escape
