An exhaust aftertreatment system may include an injector, an aftertreatment device and a mixer assembly. The injector may be configured to inject a fluid into an exhaust passageway that receives exhaust gas from a combustion engine. The aftertreatment device may be disposed in the exhaust passageway downstream of the injector. The mixer assembly may be disposed in the exhaust passageway upstream of the aftertreatment device and may include a first stage having a plurality of parallel plates and a second stage connected to the first stage and disposed downstream of the first stage. The second stage may include an auger blade. The mixer assembly may divide an exhaust stream into at least two flow paths.