Philanthropist Jerome Breen walks out of a room and goes to an office building custodian and asks what time it is. He nonchalantly leaves while the other man goes to a nearby office and finds yet another stock broker choked to death by incredibly strong hands. All would seem to point to Breen as he was seen by an eye witness, but Mr. Breen is medically a mute. Such is the story behind The Sphinx. It is a craftily-made little thriller with some comedic touches against the backdrop of a rather ingenuous mystery. Lionel Atwill plays the ubiquitous Breen and the biggest regret...not flaw, but regret..is that he has so few lines in the picture. Atwill and his use of clever timing and sardonic wit are always a major plus to any picture, yet Atwill can and does employ his facial muscles to convey much. The other actors are all strangely pretty decent with the gentleman playing the custodian, an Italian that drinks a bit, turning in a fine comedic performance. The mystery in the end is not easy to guess, perhaps a bit contrived, but wholly enjoyable.