Near the close of This Alibi's otherwise instrumental debut disc, a man intones, When it all goes dark, all you have left is what you can hear. You have to trust in that. It's an apt epigram for a disorienting listening experience. This immersing EP's impact dwarfs its 25-minute duration. After an ambient introductory track, This Alibi unravels a thick bass line, adding a few measured percussive taps and hovering guitar notes. This song, "In Vast Direction," seems extinguished after a drum flourish at the 1:30 mark, but it revives with thunderous rhythms and roaring prog-metal riffs. The trio repeats the soft-loud dynamic cycle several times, with guitarist Bob Bitner filling the serene passages with spacey experimentation. After the human voice finally makes its portentous appearance, This Alibi erupts with 30 seconds of robust noise, then ends in an ethereal haze, as if someone snapped his fingers to break the spell. See it all come alive at the Record Bar on Friday, August 18, when This Alibi plays with Vedera and the Life and Times.