The drawer opened, and Batman reached in and took out the key. This key was larger than any they had obtained before; it looked like the key to the big door outside.
"Finally," Superman said. "Now we should be able to get out, right? The more I look at that thing on your collarbone, the more uncomfortable it makes me..."
"Don't rush, Clark." Batman examined the key, then handed the iron spike he was holding to Superman. "Hold this for me."
Superman stood beside him and obediently held the iron spike for him, but he still couldn't resist leaning in to see what Batman was fiddling with. With his freed hand, Batman held the lower half of the key, while his other hand rubbed over the upper half.
"There's another mechanism on the key," Batman said. "It's dim in here, so it's hard to see. If you didn't feel it carefully, you'd probably miss it."
"A mechanism on the key? What's it for?"
Batman did not answer at first. He felt it over carefully, then showed a look of understanding and said, "There's a metal plate here. Once the metal part is turned down, the inside is wood. The keyhole may be electrified?"
"Electricity? There's electricity here?" Superman looked around in some surprise. "But this place looks like a medieval dungeon... Okay, I know what you're going to say. The killer did it to lull us into complacency."
"You catch on fast, Clark." Batman glanced at him with some approval. "I think this is the real killing move. Through all the earlier setups and foreshadowing, it made us think there would only be non-modern technological mechanisms here. But in reality, the keyhole is charged with high-voltage electricity, meant to shock us unconscious when we use the key to unlock it."