He has the strangest expression on his face- the emotional equivalent of 404 PAGE NOT FOUND.

Mac looked up with the oddest of all his odd expressions

This guy — Joe whatever — hasn’t even got the right expression on his face; he should have that cold but somehow enthusiastic look, as if he believed in nothing and yet somehow had absolute faith.

Blount’s face registered psychopathic amazement, idiot incredulity, moronic disbelief.

On his face was a queer look-the look of one who is embarrassed because he is about to say something honest.

His face had been twisted into an expression of every agony he had imagined for his friend.

...he looked so strange and absentminded; quite obviously he had just been reading a book, one could tell that from the expression in his eyes, from his hair, from the abstracted way in which he managed his hands.

He is not handsome, but looks as the author of his books should look: a little strange and odd, as if not of this earth.

The criminal clearly wasn't expecting to find me there. He looked back at me with an expression of sheer balaclava written all over his face.

Anything approaching the change that came over his features I have never seen before, and hope never to see again. Oh, I wasn't touched. I was fascinated. It was as though a veil had been rent. I saw on that ivory face the expression of sombre pride, of ruthless power, of craven terror — of an intense and hopeless despair. Did he live his life again in every detail of desire, temptation, and surrender during that supreme moment of complete knowledge? He cried in a whisper at some image, at some vision — he cried out twice, a cry that was no more than a breath:
The horror! The horror!

He is a wholly unpredictable man of many moods and great dimension, a man who responds instantaneously to instinct — suddenly, dramatically, wildly he responds, and nobody can predict what will follow.

He turns to me. There’s a look on his face that makes him appear a decade younger. A look of wonder and discovery. I remember falling in love with that look.

He turned, as he spoke, a peculiar look in her direction, a look of hatred unless he has a most perverse set of facial muscles that will not, like those of other people, interpret the language of his soul.

The lines on his forehead arrange themselves in an odd chequered pattern, like a puzzle waiting to be filled in — or are, perhaps, a reflection of his past.