Eric James Stone's Unforgettable is a fantastic spy drama that involves entanglement theory.
Somehow, because of a loophole in his quantum state, Nat Morgan is completely forgettable. No one remembers him after one minute. Even cameras and computers are unable to capture his presence or record his doings. This would seem to make Nat a perfect thief, but he's taken a job at the CIA. His handler has a special file with notes and authentication protocols so the agency can use Nat for jobs in which anyone else would be discovered.
On a dangerous mission to obtain a powerful computer chip, Nat encounters the ex-Russian spy Yelena Semyonova, who has the same objective. She's working for the mafia, who have kidnapped her sisters to keep Yelena in line, but the two spies form a temporary alliance. During their escape, Nat and Yelena become entangled on a quantum level, making Yelena the only person in the world who can remember Nat.
The pair end up rescuing a brilliant Iranian physicist and helping him defect to the U.S. He links the chip back to a billionaire Russian mafioso, who aims to create a quantum supercomputer that won't only predict the future, but also control it. The team of spies and scientist must stop this plot, which could destroy the fabric of reality with no one the wiser.
Unforgettable is a quick, delightful read with well-considered plotting and a protagonist who won't be forgotten. --Rob LeFebvre, freelance writer and editor