Bidding Problem

You are dealt AQx-void-xxx-AKQxxxx.  After opening 1C, LHO intervenes with 1H, partner bids 2D, and RHO preempts to 3H.  Your call?

On the one hand, you have 15 HCP, with a four-loser hand (three diamond losers, plus a spade loser).  Additionally, the spade finesse might fair (probably does), for five losers.  How do you explore, then, this slam?

You could get scientific and bid 4H, but what will partner think that means?  I mean, she certainly won't be excited by her clubs, because she is probably short and definitely has no honors.  She might think you are supporting diamonds, which is not really your intention, and diamonds out-rank clubs (you cannot correct any diamond bid to the same level in clubs). 

On hands like these, you sometimes have to go with general principles.  What was this 2D call?  You expect that partner probably has some heart length, probably not four spades, and probably not hearts double-stopped, because of the auctio so far.  If she has a good hand, therefore, 6C probably has play.  But, what if she has a minimum, or even sub-minimum?

In that event, you must hope that partner knows bidding and only bids with a weak hand if her diamonds are good.  So, blast 6C!  You know where you want to be, you cannot really find out what you want to find out FOR SURE by any auction that is not prone to possible confusion and disaster, and you expect that partner will have something resembling what you need anyway.

Sure enough, partner tables xxx-Qx-AQJxx-Jxx.  That's a fairly ugly hand.  Only 10 HCP, and two of them are the doubleton Queen in the opponents' suit.  But, the suit quality is really good.

If you think that the 6C call was the key action on this deal, I personally think you are wrong.  That 2D call, with a quality suit, was the key call.  Way to go Responder!