An unscrupulous creditor might sell the right to collect the same debt to two different persons by assigning it to each of them. Which one of the two innocent assignees is entitled to payment and why? What is the defense of set off and why is it important in the context of an assignment of contractual rights? The producer of a "musical on ice" show booked a large hockey arena for a local date. Immediately before the scheduled show the arena was destroyed by fire. The evidence disclosed that the cause of the fire was faulty electrical wiring that had not been repaired for which the careless owner was to blame. The producer sued the arena owner for breach of contract to compensate for losses sustained as a result of having to cancel the skating show. The owner claimed that the contract was frustrated by the fire. What will the court likely decide and why? In a contract where performance occurs over time by instalments and the initial performance is defective, what dilemma does the innocent party face and what should the innocent party do prior to making any decision?