In The Adventure of the Beryl Coronet, a banker, Mr. Alexander Holder, makes a loan of 50,000 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, he is horrified to see his son playing with the coronet and apparently trying to bend it. Three beryls are now missing from it. In a panic, Mr. Holder travels to see Holmes, who agrees to take the case.