This deal is from the South Florida Bridge Players IMP game. At favorable vulnerability, South held:

KQ9752
4
8
AKQ62
His RHO opened 1. What's your call? 

This hand is too good to preempt, though I suppose a direct 4 is possible. I'd prefer to have more strength and less freaky shape to start with double. A Michaels bid with 6 in the major and a hand like this is possible, but I prefer to just overcall 1 for now. It isn't likely to go Pass-Pass-Pass.

LHO Passes and your partner cue-bids 2. What's that? It requires partnership discussion, but let's assume you are playing my preferred way, where this shows a limit-raise or better, guaranteeing at least 3-card spade support.

My first instinct is to use Blackwood. Opposite 3 aces you can bid 7 and opposite two, you can bid a small slam. You can sign-off in 5 opposite one. If you do bid 4NT, partner answers 5 showing 0 or 3 keycards (1430). Now what?

Opposite 3, you'd like to be in 7, but you can't bid 7, in case partner has 0. The solution is to bid 5. Partner has to know that 3 is good enough (how could you ask, and then not bid slam opposite 3?). Unfortunately, when you bid 5, partner passes. That means 0, and it means you are too high.

Let's try a different route over 2. How can it hurt to bid 3, ostensibly a game try? Partner signs off in 3--or at least tries to. You're having none of that, but can make another attempt by bidding 4--it is still vaguely possible that partner has 2 aces. If he now bids 4 (as he would), you can be sure he doesn't have 2 aces (he would have owed you a control bid of 4 or 4). Now, using your mulligan, try the play in only 4:

10864 KJ6 KQJ10 108

KQ9752 4 8 AKQ62

West leads the 10 and you try dummy's jack. East wins the Q and lays down the A. You trump, and as your goal is only 10 tricks, you might as well lay down the K next. LHO throws a diamond and RHO thinks it over and ducks.  Now what?

Will you play ace-king and try to ruff a club in dummy? If it lives, you'll make an overtrick (throwing a diamond on the K and leading a spade up).

No, that is not a good idea, as the full deal shows:

Vul: East-West Dir: South	10864 KJ6 KQJ10 108
1093 976543 J943		AJ3 AQ8752 A2 75
	KQ9752 4 8 AKQ62

After East (erroneously, as it turns out) tries to cash 2 hearts, you ruff and lay down the K. East ducks, and now you must resist the temptation to reach dummy on your own. You should play the dentist. Extract East's clubs. Cash only the ace and king (hoping East has at least 2 clubs). Now, instead of a 3rd club, play a diamond. East wins, but has to give you access to dummy. If he produces another club, that's fine (you'd ruff in dummy to lead a spade up). If he plays a red suit, you win in dummy, of course, and lead your spade up yourself.

East had several ways to defeat you had he known what was going on. He had to play the dentist himself by extracting your singleton diamond at some point and then sitting back to get two spade tricks for himself.