Kool Keith, the influential rapper, is back. Last summer he vanished for several weeks, costing the critically acclaimed Dr. Octagon project a spot on the Lollapalooza tour.

Now comes word that Keith is reuniting his former group, the Ultramagnetic MC's, to record a new album due this fall.

Their 1988 album "Critical Beatdown" is considered a Hip Hop classic. The Prodigy is expected, though not yet confirmed, to guest on the Ultramagnetic MC's album. That would be fitting since Kool Keith raps on The Prodigy track "Diesel Power" on the "Fat Of The Land" album, which also samples the Ultramagnetic MC's on "Smack My Bitch Up." Also expected to guest on the Ultramagnetic MC's album is rapper Rakim.