Authors are constantly asked where they find ideas for their books, a wearisome refrain that usually yields polite, ordinary replies: from past experiences, a song fragment, a family tiff. Washington novelist Louis Bayard anticipates the question and tells readers upfront how “The School of Night,” a contemporary mystery infused with 16th-century history, flowed from a classic 21st-century time-waster: a day-trip around the Internet.

Bayard’s Google discovery of the School of Night prompted more questions than confirmations. Did a group of scholars that included Christopher Marlowe, Walter Raleigh and a young man named William Shakespeare really exist, holding clandestine meetings to debate divinity, politics, astronomy, alchemy? Such gatherings and such topics might have drawn the ire of Queen Elizabeth, so the band of scholars met at night. But they left no paper trail of their conversations, and no formal documentation shows that the School was real.

How convenient for Bayard’s modern-day characters — and how exciting for us. Their quest to learn more about the School involves academic research, treasure hunting and action adventure. Henry Cavendish, a 21st-century English professor whose career was derailed when he discovered a poem by Raleigh which proved to be a fraud, first heard of the School of Night from his lifelong friend, a wealthy man named Alonzo Wax. Wax’s fervor for the School was fueled by his delight in spotting mentions of it in Shakespearian metaphors and allusions. This interest followed the two classmates through college and reached a new intensity years later. Wax’s final voicemail message for Cavendish — “Call me. The School of Night is back in session” — is a bewildering prelude to Wax’s fatal plunge into the Potomac River hours later.

Even more baffling for Cavendish is the sudden appearance of two more School devotees. Clarissa Dale, who received the same message from Wax, claims to have nightly visions of Thomas Harriot, an obscure member of the group. Bernard Styles, an antiques collector, is trying to retrieve a stolen document that attests to the existence of the School of Night. He insists that the page, part of a letter written by Walter Raleigh, was lifted by Wax. Waving a $10,000 check and the promise of more cash, Styles persuades money-strapped Cavendish, Wax’s reluctant executor, to look for it amid his friend’s massive collection of books and papers.

At first, Cavendish’s scavenging seems casual: an amateur detective on the trail of the intangible. Then Cavendish wonders what’s really at stake when a pair of murders turns the diversion dangerous. Other characters show up with agendas and ideas all their own. The search for an ancient letter in a Washington apartment escalates into a trans-Atlantic scramble to uncover the promise of much more.

"The School of Night: A Novel" by Louis Bayard (Henry Holt. 338 pp. $25)

“The School of Night” comes into sharper focus via flashbacks sandwiched between current-day chapters. Rather than put words into the mouth of one of the more famous names, Bayard gives the lesser-known Harriot a voice. The scholar, a translator, mathematician and scientist, divulges details about his colleagues in the School and sketches a slice of 16th-century life. Harriot, dubbed “England’s Galileo,” has secrets of his own. Fearful of discovery, he holds his findings close. Only youthful Margaret, a housekeeper who becomes Harriot’s research assistant and later, love interest, is privy to his most ambitious alchemy experiment.

Its existence, perilous and exhilarating, cuts across time as Bayard knits his modern and historical storylines together. In the 21st century, the School of Night enthusiasts cull clues from what they see in the mysterious letter. Determined to capture every wisp of elusive information, they flit between certainties: They’re seeking sunken booty off the shores of the East Coast. No, it’s a hidden stash of gold tucked away in England. Or is this enigmatic treasure even grander, its value worth the risk of a human life?

Bayard adds twist after satisfying twist to these interlocked tales. Tragic and jolting surprises keep the storylines zigzagging toward resolution. At its heart, “The School of Night” illuminates a glimpse into legend, assuring readers that this ancient classroom offered a curriculum heavy on secrets.

Blumenstock is a Washington writer.