A system (200; 250; 270) has first (220) and second (222) compressors, a heat rejection heat exchanger (30), first (38) and second (202) ejectors, a heat absorption heat exchanger (64), and a separator (48). The heat rejection heat exchanger is coupled to the second compressor to receive refrigerant compressed by the second compressor. The first ejector has a primary inlet (40) coupled to the heat rejection exchanger to receive refrigerant, a secondary inlet (42), and an outlet (44). The second ejector has a primary inlet (204) coupled to the heat rejection heat exchanger to receive refrigerant, a secondary inlet (206), and an outlet (208). The separator has an inlet (50) coupled to the outlet (44) of the first ejector to receive refrigerant from the first ejector. The separator has a gas outlet (54) coupled to the secondary inlet (206) of the second ejector via the first compressor (220) to deliver refrigerant to the second ejector. The separator has a liquid outlet (52) coupled to the secondary inlet (42) of the first ejector via the heat absorption heat exchanger to deliver refrigerant to the first ejector.