An unknown language in an unknown script is the linguistic equivalent of a locked-room mystery, and despite the efforts of investigators around the globe, Linear B endured for more than 50 years as one of the world’s great unsolved puzzles.

Then, in 1952, against all odds, the script was deciphered — seemingly in a single stroke. The decipherer was an amateur, Michael Ventris, a brilliant, melancholic English architect who had been obsessed with Linear B since he was a boy. He discovered that the script was used to write a very early dialect of Greek; set down in wet clay centuries before the advent of the Greek alphabet, it recorded the day-to-day workings of the first Greek civilization.

Though Mr. Ventris’s achievement brought him worldwide acclaim, it also left many unanswered questions. He had planned to write an account of his work, describing the incremental steps that led to his inspired solution. But he was unable to do so before he died in 1956, at 34, in a swift, strange car crash that may have been suicide. As a result, the story of one of the most breathtaking intellectual achievements in history remained incomplete for more than half a century.

Like so many canonical narratives of achievement, this story has a quiet backstage figure behind the towering public one. And here, too, as in other such stories (recall Rosalind Franklin, whose work, long unacknowledged, informed the mapping of the structure of DNA by Francis Crick and James Watson), that figure is a woman.

Alice Elizabeth Kober was born in Manhattan on Dec. 23, 1906, the daughter of recent immigrants from Hungary. A brilliant student, she earned a bachelor’s degree in classics from Hunter College, and it was there, in a course on early Greek life, that she appears to have encountered Linear B.

Enthralled — and already confident of her own blazing intellect — she announced on her graduation that she would one day decipher the script. She came within a hair’s breadth of doing so before her own untimely death, at 43, just two years before Mr. Ventris cracked the code.

Dr. Kober never married, nor do her hundreds of pages of correspondence reveal the faintest glimmer of a personal life. Each night, after her classes were taught and her papers graded, she sat at the table in the house she shared with her widowed mother and, cigarette burning beside her, sifted the strange Cretan inscriptions.