They then broke the seal and entered the room by means of a master key.
The secretary of these flats, even the hall porter, should have a master key.
This is the master key to him; the main stress of his preaching and writing is here.
He decided to say nothing about the Demon or the accidental striking of the Master Key.
Why, oh why did not some intelligent person strike the Master Key!
Waiting no longer, the day watchman used his master key on the door.
The loss of the master key, which was in that safe, is irreparable.
When Raines came in he inserted the master key in the lock and opened the deposit box.
The theory of the class struggle is the master key to the bewilderments and confusions of history.
Pausing at a door, the cleaning woman fitted a master key into the lock.