Believe it or not, “Conversion,” the huge single dropped by Mefjus and Kasra last week, is actually the b side to their first single. “Decypher,” and effectively the whole single will drop tomorrow on Critical Recordings, and it’s Mefjus and Kasra’s debut single together, another surprise.

“Conversion” blew up as soon as it hit Critical’s Soundcloud. A weird and almost intelligent neuro track, “Conversion” has had drum and bass fans questioning why it’s taken so long for the Critical label head and the Austrian dnb juggernaut hadn’t gotten together on a track sooner.

“Decypher” is a surprising compliment to “Conversion,” but it stands to reason that it’s the lead track on this double single. “Decypher” is deeper than “Conversion,” if such a thing is possible, and structurally it’s a straight up drum and bass roller with a little baby neuro snap to it (thank you Mefjus). It many ways, “Decypher” and “Conversion” serve as each other’s antithesis. There’s plenty of old school cache to this track, with heavy, rolling sub bass and travelling snares which devolve into an amen loop at the break. It’s heavily mixable even with the intelligent bass vibe, and it has a really interesting outro that will likely compliment a heavy double drop on the dancefloor.

Here’s hoping that “Decypher”/”Conversion” is the first of many tracks Mefjus and Kasra release together, now that they and the drum and bass world at large know what great beats the two of them can make.

“Decypher” is now streamable on the Critical Soundcloud page, and both “Decypher” and “Conversion” will drop tomorrow, Friday 7/21 on Critical, with a limited edition 12″ also available.