Sparta's debut EP showed promise, but Wiretap Scars is a sound reward.

It fills the void where At the Drive-In was with focused post-hardcore frazzle, leaving the relentless experimentation to Cedric Bixler and Omar Rodriguez in Mars Volta and focusing instead on a terse melodic sense.

Wiretap Scars is accessible, but on Sparta's own terms.

"Mye" and "Cataract" return from the EP; the reflective "Echodyne Harmonic" has been more fully realized.

"Mye" especially reveals the influence of Fugazi's mastery of tension and release on Sparta, from the Ian MacKaye-style righteousness of Jim Ward's vocal -- "This time I'll get it right/You can't defend it, it's predetermined" -- to the song's controlled fuse volatility.

Taken with the shouty "Cut Your Ribbon" and the barbed guitars of "Rx Coup" and "Red Alibi," there's enough ATDI blood boil in Sparta to keep fans of the old stuff interested.

But Ward, guitarist Paul Hinojos, drummer Tony Hajjar, and bassist Matt Miller like melody with their rage, as the incredible break at the end of "Coup" proves.

They're also able to shift gears fluidly.

"Harmonic" is tinged with piano, and "Glasshouse Tarot" drifts through moody dynamics before intersecting with its chorus, an urgent blast close to Jawbox or Friction.

Scars could use the occasional sharpening on both ends of its sound.

But it never hides where it's coming from, and often puts its lance into gristly, rewarding hooks.

Wiretap Scars is certainly what's come after.

But with their first full-length, Sparta define just what's driving them.