Westworld is television carefully crafted to fit the zeitgeist of today. Audiences are prompted to reflect on our own encounters with big data and bourgeoning technology, and we’re encouraged to consider the high brow concepts that will likely underlie the formation of our future morals or our lack thereof. But it’s also a show that asks: What would be a really cool way to blow someone up?

Hold up: Spoilers for Westworld Season 2, Episode 4 are below. If you haven’t seen it, erase this interaction.

In “The Riddle of the Sphinx” viewers are brought back to some familiar concepts and scenarios. William’s return to the Maze is turning out to be a sort of “choose your own adventure but this time pretend you’re a better person” thing: He’s back in Lawrence’s hometown, where in Season 1, he killed the host’s wife and cousins in an effort to force Lawrence to reveal the Maze. Now, Major Craddock and his band of Confederados are the ones threatening Lawrence’s family while on the hunt for weapons, as William observes. Just as William once danced with a sobbing Mrs. Lawrence, Craddock does the same.

We also are reintroduced a substance that was a plot point of Season 1, episode five: Nitroglycerin. Then, Logan, Dolores, and William help steal nitro and hand it over to Lawrence, then playing the role of El Lazo. Lawrence promptly double-crosses them and fills up some corpses with nitro in order to turn them into body-bombs. In “Riddle,” nitro is forced into a body again — this time with William forcing Craddock to gulp up a shot of it, once he realizes that in this turn he’s more on the side of vengeful justice. William hands a shotgun to Lawrence — who moments before almost had to sip the nitro himself — and boom, a single bullet turns Craddock into robot toast.

Westworld
Goodbye Craddock.

This explosive goodbye begs the question: Could a bullet ignite an explosion in a body containing a shot of nitro? The answer is a bit of a yes and a no. Nitroglycerin is a highly explosive and unstable liquid — it’s accepted that the slightest jolt or bit of friction would cause it to detonate. Being extremely sensitive to shock in its liquid form, it’s reasonable to say that a bullet, upon impact with nitro, would cause an explosion, but it’s also likely that the forceful chugging of nitro by William would have caused a detonation as well. This wasn’t exactly a careful process:

Westworld, nitro
In real life, just a small amount of friction can cause nitroglycerine to detonate.

In comparison, this is what it looks like when a hammer ever-so-slightly touches down on some nitro. Being splashed down on Craddock’s tongue as some sort of murder-waterfall probably would have had the same effect.

Nitroglycerin
Nitro vs. a hammer's touch

What makes nitroglycerin so susceptible to detonation is what its made of: Invented in 1847 by Italian chemist Ascanio Sobrero, nitro emerged after Sobrero added glycerol to a mixture of nitric and sulfuric acids (he was also badly scarred his face when it exploded during experimentation). Within the substance is oxygen, nitrogen, and carbon. When these are destabilized upon impact, a rapid decomposition reaction happens as a supersonic shock wave passes through the material. As the energy is released, the atoms rearrange to form new molecules with stable bonds, including N2 and CO.

Sobrero made it with the intention of creating something that could be used for blasting rock in mining but almost immediately regretted it, saying: “When I think of all the victims killed during nitroglycerine explosions, and the terrible havoc that has been wreaked, which in all probability will continue to occur in the future, I am almost ashamed to admit to be its discover.” Alfred Nobel was later able to twist nitro into the more stable form of dynamite, but throughout the late 19th and early 20th century — about the time Westworld is designed to mimic — unexpected nitroglycerin explosions would kill many during its transportation.

Today, it has a different role: as an active ingredient in heart medications and treatments for erectile dysfunction. As a solid, nitroglycerin is a stable that can help people — but as a liquid, it’s an explosive better suited for revenge.