What’s the song in the ‘Westworld’ season 2 trailer?

It’s not Nirvana, it’s HBO.

The second season of the premium cable network’s breakout show, Westworld, is set to debut on April 22. A new trailer for the show has dropped, and it features a song known and loved by millions, but in a very different form.

When “Heart-Shaped Box” was first released in 1993, Nirvana was among the biggest bands in the world. The Nevermind album had already conquered radio and the charts, and the group’s new legions of fans waited anxiously for what was next.

It arrived in the form of the abrasive but still melodic “Heart-Shaped Box” single. Produced by Steve Albini, the track retained the loud-quiet dynamics found on such hits as “Smells Like Teen Spirit. With the delicate verses balanced by the brutal chorus, the track topped the Billboard Alternative Songs chart, and somewhat ironically peaking at Number 4 on the Mainstream Rock chart.

See photos of "Westworld" star Evan Rachel Wood:

For the Westworld trailer,”Heart-Shaped Box” has been reimagined by composer Ramin Djawadi, best known for his music on Game of Thrones.

As the cast of Westworld—including actors Jeffrey Wright, Thandie Newton, Evan Rachel Wood—play out their various existential crises onscreen, Djawadi’s dramatic piano and strings arrangement of the Nirvana classic plays ominously in the background.

The haunting, discordant melody of the song works well in the sweeping and symphonic form for the clip, setting the stage for another dramatic season featuring man wrestling with his own runway technology and imagination.

The musical treatment is in keeping with the show’s first season which featured Djawadi’s takes on The Rolling Stones’ “Paint it Black,” Radiohead’s “No Surprises,” and Soundgarden’s “Black Hole Sun” among others.

Watch the drama unfold below.