In a fixed-return operation, what happens if the operation earns more (or less) than expected?

You receive exactly your agreed return, in both cases. If the operation outperforms, the surplus goes to Invernova: that is the counterpart of us bearing the risk, because if the operation earned less than expected, your fixed return would remain untouched. You choose certainty in exchange for giving up the upside; if you would rather share in the profit, success-based operations are for you.