Nothing so obvious, Walt. But given Batman's importance to Crane, which I believe is a profound relevance based on a brief conversation we shared, there is no other tool that inflicts the same impact.

[A quickened beat followed, like the rhythm of a pulse.]

You and Crane shared a lab. Do you have any formula residue? Of his... Toxin? And if not -- do you understand the compound structure? Can you mimic it?