The　deformation　of　a　single-crystal　Fe48Mn32Co10Cr10　alloy　is　captured　in　situ　at　the　atomic　scale.　The　results　show　that　full　and　partial　dislocations,　along　with　deformation　twins,　are　involved　in　the　deformation　process.　Partial　dislocation　activities　result　in　the　formation　of　nanotwins,　high-density　coherent　twin　boundaries,　and　incoherent　twin　boundaries.　Full　dislocations　interact　with　the　coherent/incoherent　twin　boundaries,　and　partial　dislocations,　thereby　producing　high　strength　and　remarkable　strain　hardening.　The　observed　high　activity　of　full　dislocations　can　be　attributed　to　the　inhomogeneous　distribution　of　solid　solution　atoms　in　the　alloy.{GRAPHICAL　ABSTRACT}