Like any good pair of twins, Run the Jewels have a freaky sort of unspoken fraternity. When El-P and Killer Mike strode in with their usual uniforms — Mike in a gold chain as thick as a garter snake, El in a fitted Yankees cap and pair of blue-mirrored sunglasses — the two didn't have to do as much as nod to one another before upending three tracks from their latest LP, RTJ3, in strange and perfect symbiosis.

El-P (née El-Producto, née Jaime Meline) — rapper, producer, and all-around godfather of the backpacker scene of the late-90's — and Killer Mike — known for guest features on tracks by Atlanta's Dungeon Family in the early-aughts, solo work in the mid-to-late '00s, and perhaps most widely for his very public support of Senator Bernie Sanders' presidential campaign last year — have out-mused each other in a supergroup that somehow seems to get better, louder, and more pertinent since their start in 2013. They represent an ideal evolution of underground hip-hop to mainstream success, mixing a fundamentally activist animus with IMAX-level production without losing a speck of vital force.

On an unseasonably beautiful day in D.C., Run the Jewels was sweaty and sulfuric, ad-libbing with one another in an exchange so slick, easy, and conspiratorial, it felt like we were in on their shared language.