It tells the story of four gifted children: Reynie Muldoon, George "Sticky" Washington, Kate Wetherall, and Constance Contraire, who together form the "Mysterious Benedict Society" and are sent to investigate an institution called L.I.V.E.

[1] Reynard "Reynie" Muldoon is an orphaned boy with a love for puzzles and books living in an orphanage in the metropolis of Stonetown with his tutor, Miss Perumal.

Reynie notices a newspaper advertisement targeted towards gifted children, consisting of a series of three odd and complex tests, all of which he passes.

They explain that a mysterious threat plagues the world in the form of secret messages transmitted into people's minds via television and radio signals.

They also discover that this machine is capable of "sweeping away" memories, and that Mr. Curtain plans to boost his messages to transmit directly to people's brains.

Upon returning to Stonetown, the four children settle down and find families of their own; Reynie is adopted by Miss Perumal, Constance by Mr. Benedict, Sticky reunites with his estranged parents and Kate with Milligan, revealed to be her father.

Many critics praised the enigmatic plot and puzzles included in the storyline; journalist Michele Norris, writing for NPR, said, "Almost everything inside this book is an enigma.

"[3] Rick Riordan, author of the Percy Jackson & the Olympians series, wrote, "I enjoyed it very much -- great cast of characters, lots of cool puzzles and mysteries.