There you go, all the memes in one shot (no pun intended).
A very large-ish armoured snowglobe, with fingerprint, retina scanner and fiendish set of questions eg "A ship travels at 10 knots, the river current is 12 knots (20 in the rainy season) how long does it take to get from Amapa to Manaus if
you leave on February 19th, about teatime-ish?" etc.
Inside is the snowglobe is a lot of that fake snow, a miniature Charlton Heston banging on about "cold, dead hands" and several guns with little floats on them to achieve neutral buoyancy, only one of the guns is real.
By presenting the correct fingerprint, retina and answering as few as 97 questions correctly the actual working gun is presented to your hand, probably.