An apparatus includes an ejector, a first load, a second load, a third load, a first compressor, a second compressor, and an accumulator. The ejector directs a refrigerant to a flash tank that stores the refrigerant. The loads use the refrigerant from the flash tank to cool spaces. The first compressor compresses the refrigerant from the first load. During a defrost cycle, the first compressor directs the refrigerant to the third load to defrost the third load, the accumulator separates the refrigerant that defrosted the third load into a second liquid portion and a second vapor portion, the ejector directs the second liquid portion to the flash tank, and the second compressor compresses the second vapor portion.