His goodness would be kept a profound secret, Billy knew that.
In the first place," he continued, "you must keep the whole affair a profound secret.
The whole affair was kept a profound secret until last night.
Tucker said that she kept this "a profound secret to herself, even until after the book was published".
Or do they, as I suspect, have an even profounder secret?
We kept the game a profound secret from the other fellows.
The accounts agree that what was done and taught among the members was kept a profound secret.
"This was one of the most profound secrets of our foreign policy," he said.
This, however, was a profound secret, not to be breathed beyond their own circle.
The profoundest secrets of body and spirit were available to anyone with the itch to see.