Trip-hop's second renaissance may be in danger. While Massive Attack's Bristol contemporaries Portishead and Tricky brought the style roaring back to music's forefront with a pair of hum-dingers, Third (review) (Mercury) and Knowle West Boy (Domino) respectfully, it didn't seem too much to ask to bet on Massive Attack's return from dormancy to complete the trifecta. While the results of Massive Attack's first album in six years are still on the horizon, things aren't looking too good for the trip-hop elder statesmen on this EP.

A teaser aimed at hyping up interest in Massive Attack's long-awaited follow-up to 2003's 100th Window (Virgin), Splitting the Atom might just do the opposite: The Bristol captains of downbeat production and smoldering arrangements return to their craft with a frightfully uninspired effort. Two studio cuts, "Splitting the Atom" and "Prayers for Rain," the latter of which features TV on the Radio frontman Tunde Adebimpe handling lead vocals, join a pair of remixes, "Bulletproof Love" and "Psyche," and give fans precious little to hope for in 2010, outside of a deluxe version of Blue Lines.

Bristol's return in '08 was triggered by trip-hop's versatility and its artists' ability to find new things in themselves. Portishead did it with a paralyzing melancholy. Tricky did it with a punk/reggae/funk/hip-hop hybrid that expanded his horizons ever farther. Massive Attack tries to infuse dubstep and grime into its formula, but bobbles the attempt, an irony made all the more depressing since the band's early '90s sides laid the groundwork for the style with which Massive Attack now seems unable to come to grips.

The title track plays on a minimalist composition that pits an organ riff that quickly transforms from haunting to tedious over the course of a few refrains, while Elbow's Guy Garvey's vocals sound like they were taped as he mumbled in his sleep. It's dubbed-out classic Massive Attack, but it wouldn't even turn heads if the act released it 18 years ago. "Pray for Rain" is more inventive in its production, and Adebimpe's vocals are enough to carry the track through a moody, post-dubstep version that cranks up Massive Attack's heavy gloom without the grooves of the classic formula. It's more artistically adventurous than Blue Lines, but it's also less engaging.

Van Rivers and the Subliminal Kid's remix of "Bulletproof Love" work some textures and twist-backs into the track that are sorely missing from the two studio cuts. The more straightforward electronica elements yank Massive Attack out of its comfort zone, but it works. "Psyche (Flash Treatment)" burns with the psychological pressure, the grim determination and single-minded grooves of classics like "Unfinished Sympathy;" hopefully the original, presumably to surface on next year's full-length, does as well.

If Tricky and Portishead made us think that trip-hop artists could return from a funk or an absence, Splitting the Atom is a hiccup in those plans. Massive Attack needs an angle to reinvigorate itself, but it's nowhere to be found on this EP. Keep your fingers crossed that the duo finds it before it wraps up the new album.