There was an inexplicable amount of dust everywhere, and the rooms were musty, as though they hadn’t been aired for many days.
Her expression was curiously familiar — it was an expression I had often seen on women’s faces, but on Myrtle Wilson’s face it seemed purposeless and inexplicable until I realized that her eyes, wide with jealous terror, were fixed not on Tom, but on Jordan Baker, whom she took to be his wife.
There are no more uses of "inexplicable" in the book.
Show samples from other sources
With that he turned away and once again started inexplicably walking toward the wall.
James Dashner -- The Scorch Trials
For some inexplicable reason, those words popped into Thomas’s mind.