At the same time Mercedes reappeared, paler than before, but with that imperturbable expression of countenance which she sometimes wore.
"Probably," said Monte Cristo with his imperturbable tranquillity.
"Alas, madame," said the procureur with his imperturbable calmness of manner, "I consider those alone misfortunes which are irreparable."
The count’s anxiety was manifested by a bright color which seldom appeared on the face of that imperturbable man.
"Very well," replied M. Danglars, who had listened to all this preamble with imperturbable coolness, but without understanding a word, since like every man burdened with thoughts of the past, he was occupied with seeking the thread of his own ideas in those of the speaker.
There are no more uses of "imperturbable" in the book.
Show samples from other sources
Silas was imperturbable.
Neil Gaiman -- The Graveyard Book
Out of loudspeakers all around Zollverein, the staccato voice of the Reich grows like some imperturbable tree; its subjects lean toward its branches as if toward the lips of God.