Orange Is the New Black season 4 is deeply upsetting. It’s also the best season to date.

Orange Is the New Black’s theme song is a powerful and insistent earworm. Regina Spektor’s “You’ve Got Time” has opened every episode since the show premiered in 2013, over a stark montage of close-ups on various inmates’s worn — but defiant — eyes.

“The animals, the animals,” Spektor bursts, “trapped, trapped, trapped, ‘til the cage is full...”

Those 70 seconds are some of the most striking on television.

But now that we’re a few years into the series — with Netflix dropping the entire fourth season on June 17 — it’s become far too easy to forget that every episode of Orange Is the New Black starts with this emphasis on the sheer will it takes to withstand forced confinement. Maybe you’ll put an episode on, listen to the clanging chains that open the theme song, then make some toast while you wait for it to wrap up.

Orange Is the New Black may have felt immediately and distinctly different from every other show on TV when it premiered, with characters and storylines other series wouldn’t dream of putting onscreen, but as its phenomenon grew, its ability to surprise faded.

Until now.

Season four of Orange Is the New Black is incredibly bleak. It was so brutally hard to watch sometimes that knots would form in my stomach and stay for hours — and yet I couldn’t stop. This latest set of episodes is a powerful reminder of why this show was, and remains, so hypnotizing.

After so much time spent closely with these characters — whether new, old, beloved, or reviled — Orange Is the New Black’s fourth season digs deeper than the show ever has before, and proves incredibly hard to shake.

Power inside the walls of a prison is an intrinsically fraught concept, so it’s never been far from Orange Is the New Black’s mind. Who has power? Who doesn’t? Who wants it?

But the most important question, in the eyes of everyone from the prisoners to the guards and beyond, might be: Who deserves it?

At the end of season three, a complete collapse in Litchfield’s administration resulted in the entire prison getting taken over by a for-profit corporation. The fourth season picks up immediately afterward, throwing everything the show previously established out the window as it sifts through the aftermath. The prison is overwhelmed with new inmates, space-conserving bunk beds, and new guards who were hired mostly because — as military veterans — they come cheap.

At first, the Litchfield power struggles run in separate but parallel spheres. New warden Caputo (Nick Sandow) finds himself in over his head while trying to accommodate twice as many prisoners, not to mention Piscatella (Brad William Henke), his new, extremely harsh captain of the guard.

Meanwhile, Litchfield’s prisoners rush to establish dominance in this brand new order. A significant wave of new Dominican inmates shift the power balance to the Latinas and back Maria Ruiz (Jessica Pimentel) as their leader, allowing her to become Litchfield’s premier kingpin. Meanwhile, Piper (Taylor Schilling) scrambles desperately to keep up, to no avail. White supremacists circle the cafeteria like jerk sharks, sneering at anyone with skin “darker than a white sneaker.”

Elsewhere, Pennsatucky (Taryn Manning) struggles to keep her composure as the guard who raped her last season maintains his position. Sophia (Laverne Cox) languishes in solitary confinement, while celebrity chef Judy King (a warm but deadly Blair Brown) gets a private room to discourage any future lawsuits — which is a cruel joke to her fellow prisoners, stacked one on top of the other downstairs.

But slowly, surely, painfully, it becomes clear by the halfway point of the season that the most pressing and dangerous power struggle of all is between the guards and the women they’re supposed to be protecting.

Piscatella’s reign of no-tolerance terror is incredibly upsetting to watch — especially when paired with Caputo’s well-meaning but completely hapless attempts to push back against it. In a world fraught with gray areas and hard choices, Piscatella and his crew decide the best way to deal is to keep things black and white and never second-guess one of their decisions, no matter how catastrophic the consequences.

Under Piscatella’s leadership — and the overarching stewardship of a terrifyingly impersonal executive named Linda (Beth Dover) — the new Litchfield marching orders become never thinking of the prisoners as people but rather as faceless criminals who deserve nothing but the walls surrounding them.

Tellingly, the guards we’ve known from previous seasons know the situation is thoroughly fucked, but still barely push back.

By the time the season reaches its penultimate episode (“Animals”), we’ve seen enough of the twisted power dynamics at play that the gut-wrenching climax hits that much harder. In trying to break up a peaceful protest the Piscatella way — that is, by overwhelming force and zero mercy — a guard accidentally suffocates and kills a prisoner. (For more on this, click through at your own peril.)

Since the situation is by no means resolved by the end of the season — and in fact only escalates to far more dangerous levels — it’s safe to say that season five will be diving into the aftermath of a wrongful prison death in far more depth.

The brilliant thing about season four is how it slowly reveals that it was always telling this story. It uses the complexities of Orange’s sprawling cast to lay the foundation for every single thing that makes this senseless death possible — and so devastating.

It’s one of the most visceral moments in the series to date, but when you look back at the trajectory of the season it suddenly feels less jaw-dropping than it does infuriatingly inevitable.

The one thing you’ll likely hear about season four is that it’s “darker” than last season. It’s undeniably true.

As Vox’s Todd VanDerWerff wrote in 2015, last season ended at a crossroads of hope and dread. On the one hand, a guard walkout and a missing fence made way for the inmates to wander out of prison and into a neighboring lake for an unprecedented afternoon of pure fun. On the other, the waves of inmates arriving as Litchfield became a for-profit prison allowed a dark cloud to creep over one of the series’ most exuberant moments to date.

The first three seasons never sold prison as some carefree getaway, though a sleepaway camp vibe definitely crept in a little more with every new season. But season four only heightens the sense of imminent doom that came with the new set of prisoners — and the new kinds of brutal administrative policies a for-profit prison will adopt in the name of saving a dollar.

The new status quo and even more skewed power balances within the prison doesn’t just test every single character. It pushes all of them to their limits, and eventually throws them right the hell off the cliff they’ve been teetering on the edge of.

Tellingly, season four leans the least on flashbacks to the prisoners’ pre-prison lives. They still crop up, giving new insights into characters we already thought we knew, like the frenetic and mentally unstable Lolly (Lori Petty), glam sweetheart Maritza (Diane Guerrero), and the surly and defiant Flores (Laura Gómez).

But the episodes don’t need flashbacks to drive the story anymore. Though we get brief escapes to the past, this season of Orange Is the New Black feels more confined within the walls of Litchfield than any other, which makes sense, since the new order of things makes everyone feel more trapped than ever.

This isn’t to say that there aren’t more hopeful moments. Orange Is the New Black has always found pockets of joy — both pure and weird — in the darkest of places. The bonds of friendship forged within Litchfield’s walls are fierce and wonderful, and there’s probably no other show in which a scene of women dismembering a body would be set to Papa Roach’s “Last Resort” (“cut my life into pieces, this is my last resort!”).

But if nothing else, season four is here to remind us all that an addictive show about prison is still a show about prison, a place that consciously strips people of their humanity. It isn’t a sleepover, and it isn’t an escape. It’s a very real, horrifying, suffocating reality.

These women are trapped, trapped, trapped, ‘til the cage is full.

Four seasons of Orange Is the New Black are now streaming on Netflix.