Blindspot has spent an entire season building anticipation and expectations for a real heroes vs. Shepherd (Michelle Hurd) face off. Despite some so-so plotting in the early part of the calendar year and well-intended stalling in recent weeks, the wonderfully titled "Mom" generally met those expectations.

The show faced a challenge in crafting Sandstorm's assault on the squad's FBI office: making Shepherd look cunning and merciless without making Weller (Sullivan Stapleton), Jane (Jaimie Alexander) and everyone else on the team look silly. That's not easy to do, especially with stories about skilled terrorists with ideations about ending the world. Blindspot has never shied away from illustrating Shepherd's power — she did escape foreign custody almost single handedly a few episodes back — but the team needed to put up a real fight.

They did, to an almost perfect degree of failure.

"Mom" was simply a well-structured affair that built nicely from last week's events and seemingly set things up for an even more explosive finale. After Jane was forced to toss an angry Roman (Luke Mitchell) back into his cell, Zapata (Audrey Esparza), still fuming over her undercover stint in prison, pushed the issue with the weaselly Parker (Jefferson White). His info led Jane and Weller to a secret location where part of Sandstorm's plan was finally revealed: an all-out attack on multiple Department of Homeland Security HQs.

From there, things quickly took a turn for the worse. With Jane and Weller scoping out a reconstruction of the team's office, Shepherd brought an elite killing squad to the real office — and kill did they. While it's hard to fully buy into mass assassinations when the villain just picks off no-named day players, the episode smartly and regularly showed the reactions of Patterson (Ashley Johnson) and Zapata as Shepherd opened fire.

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Among the victims was Dylan Baker's rarely seen Director Pellington, a character that didn't exactly matter even as far as authority figures go. Nonetheless, when given the chance to let it rip, the excellent Baker suddenly made Pellington seem like one of the toughest/stubbornest men in the FBI, for whatever that's worth. He and Michelle Hurd had a strong series of scenes together, amid the bloodshed.

Also productive was the easy choice to split characters up into sub-groups — in different locations — throughout the episode. Zapata and the conveniently-in-the-office Reade (Rob Brown) continued to put pressure on their combustible relationship. Between the bullets flying, the former chastised the latter for thinking he should transfer to Quantico because his newfound emotions might make him weaker in the field. And wouldn't you know it, Reade was forced to react in the moment, saving Zapata from surefire death after she was wounded.

Meanwhile, Jane and Weller continued their similarly dysfunctional thing. After initially blaming one another for the ill-fated decision to lie to Roman about who wiped his memory, the two hashed it — and other issues — out as they fought their way back into the FBI building.

It's really simple to divide characters up, put them in an intense situation and make them figure out their issues. But it's also really effective. Like with everything on Blindspot, there have been bumpy spots with the development of both relationships, but you can't knock the attention spent on them throughout the season. The concluding scenes here — with Reade shifting back into hero mode and Weller and Jane kissing — felt about as earned as possible. Blindspot deserves credit for making those moments count.

Altogether, the team's work didn't stop Shepherd from killing Pellington or from breaking a completely messed up Roman out of his cell. There were major casualties and a free, angry Roman will surely be a problem in the very immediate future. But the team's heroics — including Patterson getting the message out to other DHS sites targeted for attack — kept Sandstorm's initial wave under some control.

Blindspot Delivered Some Authentic Jeller Moments in a Fun Episode

Of course, this being a show where nothing is ever what it seems, the final five minutes delivered major updates for those of you desperately seeking that Truman Protocol intel. Once the hysteria subsided, Weller was absconded by the Secret Service and taken to an underground bunker where he was officially inducted into COGS, or the Continuity of Government Subcommittee. There, he learned that he's part of the small group tasked with succeeding the U.S. government in the chance that it suffers a Phase 2-like attack.

What's this succession plan called? The Truman Protocol of course.

While Weller's cohort appears unfazed by this news, it hit him like a ton of bricks: Getting Weller (and all these other folks) in a bunker, the Truman Protocol, all of this nonsense — it's explicitly part of Shepherd's Phase 2 plan. So apparently, Phase 2 has sub-phases. Or is this now Phase 3?

These questions are sure to be answered in next week's season finale. If that hour is as strong and propulsive as this one, at least Blindspot will go out on a high note. Oh, and in case you missed it, the fun will continue later this year as Blindspot was renewed for a third season.

Blindspot airs Wednesday nights at 8/7c on NBC.