Dr. Dre and Nas got some heat in the vault.

Nas came through with his latest project, King’s Disease this past weekend. The rapper’s new project, in collaboration with Hit-Boy, was a surprising comeback following the Kanye West-produced Nasir and Lost Tapes Vol. 2 that came out last year. Hit-Boy masterfully cooked up production that perfectly fit Nas’ aged vocals and refined storytelling abilities. With a tracklist filled with the new generation of rappers, from Lil Durk to Fivio Foreign, the most surprising collaboration was The Firm’s reunion song, “Full Circle” that featured a surprise verse from Dr. Dre.

Earlier this month, a picture of Nas and Dr. Dre in the studio cooking up hit the web, though it wasn’t entirely clear at the time what they were working on. Some may have presumed that it was “Full Circle” but it appears they have some more music that they’ve been working on. Music industry vet Breyon Prescott shared some footage from Dr. Dre and Nas’ studio session earlier this month. While the track’s playing back, and Nas steadily bopping his head, Dr. Dre sits at the boards with a pensive look on his face. Nas is snapping on this record but it also sounds like Dre squeezed in a few bars as well. Check the snippet out below.