enigma

It is an enigma to me.

Russia is a riddle wrapped in a mystery inside an enigma.

Only the capture of an Enigma machine and the invention of radar could spur a fightback.

Hieratic life and writing experience best answer his enigma of renouncing the family.

The disappearance of the famous painting remains an enigma.

She is an enigma, always keeping her thoughts to herself.

The enigma of the Bermuda Triangle has puzzled scientists for years.

His sudden resignation from the company is an enigma to everyone.

The ancient ruins hold many enigmas waiting to be unraveled.

The enigma surrounding the missing hiker deepened as the search continued.

The true identity of the masked vigilante remains an enigma to the public.

The enigmatic smile on her face hinted at a hidden secret.

The enigma of the universe continues to intrigue astronomers and physicists.

Deciphering the enigma code was a crucial turning point in World War II.