Musa entered into a contract to supply two cows to Aro. Before the agreed date of supply and without the knowledge of the two parties, thieves stole the cow...

A contract can be brought to an end by frustration when, after the agreement is made, an unforeseen event beyond the control of either party makes it impossible to carry out the contract. In this scenario, Musa and Aro had a valid agreement to supply two cows, but before the delivery date and without either party's knowledge or fault, thieves stole the cows. Since neither party caused this event and it made performance of the contract genuinely impossible, the contract is discharged by frustration, and neither side is held liable for failing to complete it.

The other terms describe situations involving fault or completion, which do not apply here. Default and breach both involve one party failing to honour their obligations through their own action or inaction, but here neither Musa nor Aro did anything wrong; the loss was caused entirely by an external event, the theft. Performance would apply if the cows had actually been delivered as agreed, which did not happen.

Examination reminder: frustration always involves an event outside both parties' control that destroys the subject matter or purpose of the contract; if either party is at fault, the correct term becomes breach or default instead.