When Kenny Boone, 84, becomes the subject of a Silver Alert after abandoning his truck and wandering on foot for hours, his daughter moves him to a senior living community in Galveston, Texas. Lonely, confused, and battling dementia, Kenny finds comfort solving puzzles in the facility's game room, and quickly earns the nickname Puzzle Man. One morning Kenny opens the newspaper and sees "Help Me" written in the squares of the puzzle. Over time, a dozen more messages make a convincing cry for help. Puzzle Man is in a race to identify the mystery puzzler and render assistance before his own diminishing memory takes him out of the game.