The entirety of Sweet Nothings features oodles of Plini's fretboard-melting guitar work, so picking a song today is kinda hard, but in the end the weird groove of the main riff to "Away" has my vote. Labyrinthine and relentless, it drives the song forward like a intricate, mellow train. It would be right at home in a metal song, but instead Plini gives it a different, laid-back intensity. If that makes any sense.
The only problem for you is that I can't seem to find an upload of just this track, so you'll have to listen to the whole EP stream to hear what I'm talking about. Oh wait, that's not a problem at all.