Earth has survived catastrophic solar winds under the protection of the Grid, its planetary defense shield. Kim Saeha, an employee of the Bureau, encounters a murderer. Jung Saebyeok, a detective, is dispatched to arrest the murderer. While in pursuit of the fugitive, she witnesses an unbelievable phenomenon: The founder of the Grid—a ghost of the past—has reappeared after 24 years [since her invention of the Grid]. But why is she abetting the fugitive? This is a thriller that pursues the mysterious truth behind what saved humanity from an apocalypse.