As an investor, I wouldn't want to get any closer to Blockbuster's (NYSE: BBI) patently stupid effort to buy Circuit City (NYSE: CC) than I have to.

But HBK Investments -- which owns 9% of Circuit City, 8% of the class A stock of Blockbuster, and 5% of the company's class B stock -- has filed a 13-D on the matter, attaching a letter urging Circuit City to give Blockbuster access to the material it needs to perform due diligence. HBK added that if Blockbuster withdraws its offer because of a lack of cooperation by Circuit City's Board, "we believe Circuit City shareholders will be immediately and substantially damaged."

The fund also added that it might be able to provide financing for the deal, and expressed its confidence in the prospects for a combined company: "We believe that over $300 million per year in increased EBITDA could be realized following an acquisition by maximizing cost savings between Circuit City and Blockbuster."

That's a pretty impressive suggestion, and one that flies in the face of what many analysts have said about the proposed deal. But HBK didn't grow to around $14 billion in assets with stupid decisions, so maybe they're onto something.