An airfoil (500, 600, 1000) for a gas turbine engine, the airfoil comprising: an airfoil body (502, 602, 1002) having a leading edge (504, 604, 1004) and a trailing edge (506, 606, 1006); at least two serpentine flow cavities (510, 512, 514, 610, 612, 614, 1010) formed within the airfoil body; a resupply cavity (524, 624) fluidly connected to one serpentine flow cavity of the at least two serpentine flow cavities and arranged to supply a resupply air (522, 622) to the one serpentine flow cavity through a resupply bypass hole (628, 1028); a junction (526, 626, 1026) defined at a location where the resupply cavity fluidly connects to the one serpentine flow cavity; a separator rib (630, 1060) within the airfoil body and fluidly separating part of the at least two serpentine flow cavities; and a plurality of crossover ribs located between the resupply bypass hole and the separator rib; wherein the junction includes a plurality of crossover apertures formed in the separator rib and the plurality of crossover ribs, and defined in part by the plurality of crossover ribs; and wherein the at least two serpentine flow cavities comprise: a first serpentine cavity (510, 610, 1010) formed within the airfoil body and defining a portion of a serpentine cooling flow path and enabling a cooling flow in a first direction within the airfoil body; a second serpentine cavity (512, 612) fluidly connected to the first serpentine cavity and defining another portion of the serpentine cooling flow path and enabling a cooling flow in a second direction; and a third serpentine cavity (514, 614) fluidly connected to the second serpentine cavity and defining another portion of the serpentine cooling flow path and enabling a cooling flow in at least one of the first direction or a third direction, wherein a serpentine cooling air flows through the serpentine cooling flow path, wherein the resupply cavity is fluidly connected to the third serpentine cavity and the junction is located where both the second serpentine cavity and the resupply cavity fluidly connect to the third serpentine cavity. an airfoil body (502, 602, 1002) having a leading edge (504, 604, 1004) and a trailing edge (506, 606, 1006); at least two serpentine flow cavities (510, 512, 514, 610, 612, 614, 1010) formed within the airfoil body; a resupply cavity (524, 624) fluidly connected to one serpentine flow cavity of the at least two serpentine flow cavities and arranged to supply a resupply air (522, 622) to the one serpentine flow cavity through a resupply bypass hole (628, 1028); a junction (526, 626, 1026) defined at a location where the resupply cavity fluidly connects to the one serpentine flow cavity; a separator rib (630, 1060) within the airfoil body and fluidly separating part of the at least two serpentine flow cavities; and a plurality of crossover ribs located between the resupply bypass hole and the separator rib; wherein the junction includes a plurality of crossover apertures formed in the separator rib and the plurality of crossover ribs, and defined in part by the plurality of crossover ribs; and wherein the at least two serpentine flow cavities comprise: a first serpentine cavity (510, 610, 1010) formed within the airfoil body and defining a portion of a serpentine cooling flow path and enabling a cooling flow in a first direction within the airfoil body; a second serpentine cavity (512, 612) fluidly connected to the first serpentine cavity and defining another portion of the serpentine cooling flow path and enabling a cooling flow in a second direction; and a third serpentine cavity (514, 614) fluidly connected to the second serpentine cavity and defining another portion of the serpentine cooling flow path and enabling a cooling flow in at least one of the first direction or a third direction, wherein a serpentine cooling air flows through the serpentine cooling flow path, a first serpentine cavity (510, 610, 1010) formed within the airfoil body and defining a portion of a serpentine cooling flow path and enabling a cooling flow in a first direction within the airfoil body; a second serpentine cavity (512, 612) fluidly connected to the first serpentine cavity and defining another portion of the serpentine cooling flow path and enabling a cooling flow in a second direction; and a third serpentine cavity (514, 614) fluidly connected to the second serpentine cavity and defining another portion of the serpentine cooling flow path and enabling a cooling flow in at least one of the first direction or a third direction, wherein a serpentine cooling air flows through the serpentine cooling flow path, wherein the resupply cavity is fluidly connected to the third serpentine cavity and the junction is located where both the second serpentine cavity and the resupply cavity fluidly connect to the third serpentine cavity.