Galileo, who is by now totally blind and terminally incarcerated by the Holy See, contemplates how he might go about the seemingly impossible challenge of informing humankind of his greatest discovery. Calling upon his unfailing intellect, he devises an ingenious solution. Summoning his student whom he suspects of being the Pope's spy, he induces him to transcribe an exceedingly complex riddle obscurely imbedded within a lengthy verse. Purloining the dictated document, he awakens in the dead of night and deposits it in a secret drawer within his credenza. A short time thereafter he passes away.
Nearly four centuries later, eccentric American Professor Paul Woodbridge, a world-renowned expert on Galileo, is ensconced within his office on the campus of Case Western University when he receives a phone call. Identifying herself as Contessa Antonietta Floridiana, she summarily informs him that a document in her possession may be the final message left by Galileo prior to his passing, and although it appears to be genuine, it is decidedly indecipherable. Doubting such a preposterous possibility, Professor Woodbridge is nonetheless induced by the Contessa's disarming persistence to immediately fly to Italy to peruse the document in question.
It soon becomes apparent that the document charges them with a circuitous expedition of sorts, one that will require them to visit each of Galileo's abodes. In each destination, they expect to find clues for solving the related verse, and the succession of clues, like the dropping of breadcrumbs, will hopefully unravel the hidden meaning within the riddle.
