Adventure of the Beryl Coronet

In The Adventure of the Beryl Coronet, a banker, Mr. Alexander Holder, makes a loan of 50,000 pounds to a socially prominent client, who leaves a beryl coronet - one of the most valuable public possessions in existence - as collateral. Feeling that he must not leave this rare and precious piece of jewelry in his personal safe at the bank, he takes it home with him. Awakened by a noise in the night...