The Final Grin of the Mona Lisa

Pierre, a veteran night guard at the Louvre, has walked past the Mona Lisa for seventeen years, until one night she taps on her bulletproof glass and sheds a tear that leaves behind a golden disk. Its inscription warns that a door will open on the day her smile fades, and an alarm soon leads Pierre to a stone door sealed for five hundred years. As faces and memories begin vanishing from the world, he must uncover what Leonardo hid inside the painting and how it is tied to his own past.