Sorry to disappoint all you weekend witches out there, but you won't be learning any useful hexes in Black Mass. Such sorry. Much apologies.

That is, unless you're an amateur witch who's also into organized crime, in which case you better start taking notes. Whitey Bulger will teach you everything you need to know.

Bulger was the most notorious gangster Boston has ever seen. From the 1970s to the 1990s, he ruled the city's criminal underworld with an iron fist, dominating the gambling market, overseeing the flow of drugs into the city, and whacking anybody who looked at him the wrong way. It didn't matter if you were an average street tough or a multimillionaire businessmen—those who crossed Whitey ended up capped.

But Bulger has a dirty little secret—he was an FBI informant the whole time.

Brought into the fold by agent John Connolly and supported by Connolly's supervisor John Morris, Bulger fed intel to the Feds for decades, using the relationship to give himself a leg up on the competition. Rival gang getting strong? Rat them out. Whitey's name lands in an indictment? Connolly will take care of that, lickety-split.

So yeah, it's a twisted situation—not to mention a huge scandal for the FBI. To protect its own butt, the FBI covered up its relationship with Bulger for decades until a hard-nosed prosecutor named Fred Wyshak arrives on the scene and busts everything into the wide open.

Adapted to the big screen in 2015 with a stellar performance of Johnny Depp as Whitey Bulger, Black Mass tells a true tale that would seem unrealistic if it wasn't penned by two Boston Globe writers. Authors Dick Lehr and Gerard O'Neill channel their skills as journalists into the book, condensing an insane amount of real information into a tasty, easy-to-consume package.

So put away your magic wand, put the broom back in the corner and, for the love of all that is holy, throw that eye of newt down the garbage disposal.

You'll need a lot more than that if you want to roll with Whitey Bulger.

We'd all like to think that our leaders have our best interests at heart, but that isn't always the case. As we're reminded throughout Black Mass, powerful people are still people—and no person in human history has ever been perfect.

In fact, many—like the people discussed in Black Mass—are about as far from perfection as you can get.

Each of the players in the saga of Whitey Bulger are driven by personal motivations. John Connolly is driven by his childhood adulation of his neighbor, Whitey Bulger. John Morris is driven by a desire to be one of the cool kids for once. Even Whitey's brothers—businessmen and politicians, the lot of them–risk their careers to protect a gangster simply because he's their big bro.

Of course, none of these folks consider how their actions impact Boston at large. Whether we're talking about the business Bulger steals, the drugs he ships into the city, or the people he straight up murders, Whitey drops some dirty deeds on his hometown. No matter how personal Connolly and Morris' decision to aid Whitey might be, the impact of their choice is societal. Heavy.

This doesn't mean that you should never trust someone in charge—but you should remember that they're people too. They have friends and family. They have hopes and dreams and disappointments aplenty. They're fallible and oftentimes weak. They have secrets.

To quote the words of the iconic children's book, everybody poops.

So maybe approach authority with a healthy bit of skepticism. Maybe make it a point to stand up to things that seem unjust. It might be difficult, but as Black Mass shows us, it's the only way to create positive change around us…and to avoid falling prey to sociopaths like Whitey Bolger.