In coordination with Allison Blake's first day as leader of Global Dynamics, the facility's massive computers undergo an eight-hour reboot, audit and reset. While the computers are offline, Global's storage vault supervisor, Victor, reports that a suspicious blank spot has been discovered on a shelf. An item is missing.
Jack investigates under the stern eye of Gen. Mansfield, who is in town to supervise Allison's first day in charge. Soon, Jack discovers Fargo hiding in a bathroom. Someone left the missing device in Fargo's coat pocket, and Fargo - being Fargo - was overcome by curiosity and turned it on. Now he is trapped within an expanding force field that he can't switch off.
The device, a personal shield known as a Multi-Application Combat Armor Alternative (M.A.C.A.A.), has been flagged as dangerous, but no one currently employed at Global Dynamics knows much about it. Jack turns to Stark, who grudgingly leads him to a remote lakeside cabin where Dr. Todd, who developed the device, lives and fishes in monastic solitude.
Todd explains that, during a test, the M.A.C.A.A.'s force field couldn't be shut down. Instead, it grew relentlessly, displacing everything in its path, until Eureka itself was threatened. To stop it, Todd's team dropped the device - with a man still inside - into a deep pit known as Section 14. Then they chased it with a nuclear bomb. Although his actions saved Eureka, Todd still suffers guilt about the test subject's horrible death.
Mansfield pressures Allison to transport Fargo to Section 14 and prepare another nuke. Jack defiantly refuses to give up hope, but situation is bleak. A gooey, quick-drying epoxy fails to slow the force field's growth. Even when Jack and Lupo expose the thief who tried to frame Fargo by planting the M.A.C.A.A. in his pocket - Victor, the vault supervisor - they're still no closer to shutting the device off.
As everyone gathers at Section 14, Jack notices that the force field isn't growing as fast as Todd predicted. Jack, Henry and Stark quickly realize that the M.A.C.A.A. was stored for years next to another device that emits a magnetic field. With Todd's reluctant help, Henry rigs a matching field near Fargo and disrupts the M.A.C.A.A.'s primary power source. To Fargo's joy, the field shrinks.
Unfortunately, the M.A.C.A.A. was designed to seek out alternative power sources automatically, and that's exactly what it does: It starts sucking electrical energy from Fargo's body, and it won't stop until Fargo is dead.
Wormholes start popping up all over, threatening to rip Eureka apart unless Carter can stop them.