Sun, Sea and System – the answer
Let's assume the ♦K is led - you'll see it transposes. Win ♦A, ♣A, ♠A, ♠K, ♥A and ruff a club, now lead a spade:
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- 96
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- QJ1097
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- 8
- QJ9842
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N
W
E
S
- Q8
- Q10
- 75
- 8
- 952
- KJ5
- 6
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It does West no good to ruff in front of dummy (over-ruff, throw diamond on club, trump finesse and concede a spade) so he discards and you ruff in North. Now lead a top club and throw a diamond. West has to ruff this and lead a diamond. Throw a club and ruff in South. Now ruff the last spade; North has the lead:
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- ---
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- J109
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- J98
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N
W
E
S
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- Q10
- 7
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- 9
- KJ
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East can ruff the club but there's no trick for the defence.