Fluid-flow machine with a main flow path having a main flow path width, with an inner and an outer main flow path boundary and with at least one rotor or stator row with hybrid profile configuration arranged in the main flow path and formed by blades, wherein the blades are split in the direction of their blade height into the inner boundary area IRB defined between the inner main flow path boundary HBi and a nearby inner meridional flow line profile section MSLi, the outer boundary area ARB defined between the outer main flow path boundary HBo and a nearby outer meridional flow line profile section MSLo, and the central area defined between the inner meridional flow line profile section MSLi and the outer meridional flow line profile section MSLo, - wherein at least one of the meridional flow line profile sections MSLi and MSLo is provided at a distance of max. 35% of the main flow path width from the respective main flow path boundary, - wherein the blades have in at least parts of the central area a multi-profile configuration such that at least two partial profiles (7, 9, 10) arranged one behind the other in the flow direction are provided, of which each has substantially the shape of a blade profile, - wherein a passage is provided between each two partial profiles and is passed through by fluid from the blade pressure side to the blade suction side, - wherein at least one passage has, along the blade height, a variable passage width d, - wherein a local value of the passage width d is measured by the smallest distance that can be determined by inscribing a circle between the contours of two adjacent partial profiles on the same radius, - wherein the development of the passage width d along the blade height assumes a maximum value in at least one of the inner and outer boundary areas IRB and ARB, - wherein in at least one of the inner and outer boundary areas IRB and ARB, a changeover from the multi-profile configuration to the single-profile configuration is provided when viewing the blade profile section geometry in the direction of the main flow path boundary adjoining the respective boundary area (IRB or ARB) and the at least one passage ends at the point of changeover confined by a flank surface FF, - wherein a part of the edge of the flank surface FF is designed as an SSFFK edge on the blade suction side, - wherein a part of the edge of the flank surface FF is designed as a DSFFK edge on the blade pressure side and a distance greater than zero is provided between the pressure-side flank surface edge DSFFK and the main flow path boundary, - wherein at least one of the boundary areas IRB and ARB is provided at a fixed blade end provided with shroud or blade root, characterized in that the suction-side flank surface edge SSFFK is at least partially closer to the main flow path boundary of the respective boundary area (IRB or ARB) than the pressure-side flank surface edge DSFFK, resulting in a course of the flank surface FF inclined relative to the circumferential direction u and/or the meridional direction m and - in the flow direction - to the main flow path boundary. - wherein at least one of the meridional flow line profile sections MSLi and MSLo is provided at a distance of max. 35% of the main flow path width from the respective main flow path boundary, - wherein the blades have in at least parts of the central area a multi-profile configuration such that at least two partial profiles (7, 9, 10) arranged one behind the other in the flow direction are provided, of which each has substantially the shape of a blade profile, - wherein a passage is provided between each two partial profiles and is passed through by fluid from the blade pressure side to the blade suction side, - wherein at least one passage has, along the blade height, a variable passage width d, - wherein a local value of the passage width d is measured by the smallest distance that can be determined by inscribing a circle between the contours of two adjacent partial profiles on the same radius, - wherein the development of the passage width d along the blade height assumes a maximum value in at least one of the inner and outer boundary areas IRB and ARB, - wherein in at least one of the inner and outer boundary areas IRB and ARB, a changeover from the multi-profile configuration to the single-profile configuration is provided when viewing the blade profile section geometry in the direction of the main flow path boundary adjoining the respective boundary area (IRB or ARB) and the at least one passage ends at the point of changeover confined by a flank surface FF, - wherein a part of the edge of the flank surface FF is designed as an SSFFK edge on the blade suction side, - wherein a part of the edge of the flank surface FF is designed as a DSFFK edge on the blade pressure side and a distance greater than zero is provided between the pressure-side flank surface edge DSFFK and the main flow path boundary, - wherein at least one of the boundary areas IRB and ARB is provided at a fixed blade end provided with shroud or blade root,