We last saw Sarah Kerrigan’s fragile human body cradled in ex-marshal-turned-pirate-renegade Jim Raynor’s arms after the climactic battle on Char that saw the Swarm dispersed and the Queen of Blades finally defeated. Today, we finally have a sneak peek of the second act of the StarCraft II trilogy.

While Kerrigan is no longer an unstoppable human/Zerg hybrid who can crush battlecruisers with her mind, she is still an immensely powerful psionic. You might think that Heart of the Swarm would follow a different character after Wings of Liberty’s cliffhanger ending, but no. Kerrigan is back leading the Zerg (though she is looking pretty human these days) for reasons Blizzard declined to divulge. The two missions I played have Kerrigan traveling the Koprulu sector, reuniting the broods under her -- and gunning for the bloody dictator who abandoned her to the Zerg’s tender mercies in the first place.

Both missions feel very StarCraft II. The Char level pits Kerrigan against a rival brood mother in a race to collect eggs (it is quite similar to Warcraft III’s Stratholme mission), while the frozen moon of Kaldir sees Kerrigan’s Zerg obliterating a series of Protoss bases to prevent their psionic spires from getting a detailed message back to the main Protoss force on Shakuras. Both have secondary objectives with nice persistent bonuses, like mutation points for upgrading your units between missions or permanent stat increases for Kerrigan.

The biggest gameplay difference in Heart of the Swarm is Kerrigan herself. Unlike Raynor, she leads from the front, clearing the way with psychic blasts and her trusty canister rifle. As part of her connection with the Swarm, she can be reincarnated if she falls on the battlefield, so you have no excuse not to throw her into the thick of things. Like traditional RTS hero units, Kerrigan has a boatload of health and armor, strong attacks, and a selection of spell-like abilities.

Rather than progressing through skill trees, Kerrigan chooses from one of a number of focuses before each mission. Blizzard emphasized that the particulars will likely change before the game comes out, but the build that I played had two focuses unlocked out of four, with two or three abilities out of five total for each focus available. One of the two demo missions had a secondary objective that unlocked a new ability within one of the focuses, so it’s safe to assume that the focus mechanic is a big part of the campaign’s progression.

In her Spec Ops mode, Kerrigan got an area-effect short-cooldown psionic stun blast and the ability to create a clone of herself with a fair amount of health and who shot for half of Kerrigan’s damage. With her Corruption focus, she had the same Broodling ability as the old StarCraft I Queen: instantly killing an enemy and spawning two temporary units from its corpse. Corruption also had a acidic area debuff that made affected enemies take +4 damage, which is more helpful than you’d think with a Zergling-heavy army.

Both focuses were fun to play with. In both modes, Kerrigan functions as a tough-to-kill, powerful caster unit. I slightly favored Spec Ops mode simply because stunning a bunch of units for a few seconds seems like it scales better against larger armies, but Corruption was solid itself. I love the decision to let players freely switch focuses between missions; experimenting with different hero loadouts is always a big draw for me.

Like in Wings of Liberty, players slowly unlock units and upgrades to fill out their armies with troops that would never make it through the game’s hardcore multiplayer balancing. Zerg unit mutation is more dramatic, though. After choosing two upgrades, you can spend two more mutation points to evolve the unit into one of two forms. Zerglings, for instance, can upgrade to spawn three units per egg or gain 10 health and a jump attack.

Heart of the Swarm is definitely a Zerg version of what you’re familiar with from Wings of Liberty, but what I’ve seen makes me confident that Blizzard is well on track to adding a distinctive Zerg flavor to the existing StarCraft II single-player experience.

Want more Heart of the Swarm? Check out the teaser trailer below, or swing by the site later for more plot speculation, detailed walkthroughs of the demo missions, and a closer look at Kerrigan herself.