Quickly striding to the door, Holmes opened it to discover Doctor Watson leaning forward on one knee.
"What is it, Watson?" he asked his dear friend, as concern battled with curiosity.
"I believe this fell from my newspaper, Holmes!" Doctor Watson exclaimed, drawing back to allow Holmes a clearer view.
Pulling a white handkerchief from his pocket, Holmes lifted the heavy key, then unfurled the handkerchief for a more detailed look.
"From the wear marks on the top and side of the bow, this key appears to have been secured on a thick ring with other large metal keys.
This though," Holmes said, indicating a very fine gold chain wound through the bow of the key, "could not have supported its weight."
Holmes closed his fist slowly around the handkerchief and its contents, tapping them gently on his chest.
Turning, he reentered the apartment, calling behind him, "But tell me, Watson, what else did you find out?"