The Cold Chain is the main questline of World Z. It is one long road trip across the United States, from the mountains above Malibu in California to Oak Ridge in Tennessee. It has 12 quests. Each quest is offered only after the one before it is done.
It starts with Monique Whitlock, a kind and funny former Lifeline nurse who carries a white cooler she never lets out of her sight. She is trying to get home to her family in Atlanta. The players walk her east. On the way they keep the cooler cold, stay ahead of the Lifeline men who hunt her, and cross dead cities, deserts, rivers and horde land.
The cooler holds frozen blood samples from Nell Avery, the girl who cannot be infected, and a first batch of test serum made from them. Dr. Leon Hartley made it in a hidden lab above Malibu Canyon. It is a vaccine that needs only her blood, not her life. Lifeline took Hartley. Monique ran with the cooler.
The end goal is a sealed lab at Oak Ridge that still works, kept clean for thirty years by Dr. Carmen Lowry and her people at Melton Hill Dam. There the samples can become the first real vaccine doses. A full batch needs a pint of Nell's blood every two months, so Nell has to stay alive. That changes the whole world. Lifeline and Continuity Command will both want the lab once they hear of it.
The Canyon Lab, Easy. Monique at Malibu Creek Camp. Get the notebooks, ice packs and solar panel from the raided lab.
The Rail Cart, Easy. Rudy Salcedo at Barstow Rail Yard. Clear the line and ride his pedal cart toward Las Vegas.
The Compact Price, Medium. Diane Castillo at Hoover Dam. Win a cold box and passes from the Gate Compact while Lifeline and Continuity watch.
Ice from the Lava Cave, Medium. Teresa Baca at Bandera Ice Cave. Get ice from the cave under the lava fields.
Eyes on the Peak, Medium. Monique at Sandia Peak Camp. Get past Nolan Price and his Retrievers, who watch the highway.
The Blue Truck, Medium. Lorraine Pike at Amarillo Packing Plant. Earn the last working cold truck in the Panhandle.
The Tinker Hangar, Hard. Travis Pike at Tinker Air Base. A dead city run for a cold unit part, and a betrayal.
Ahead of the Horde, Hard. Odell Freeman at Central High Camp in Little Rock. Get out ahead of a moving horde.
Across the Mississippi, Hard. Odell at Memphis Bridge. Cross the river on his barge.
Past the Burners, Hard. Monique at Opryland Burner Camp. Get through the Burners, who want to burn the cooler.
Dead in the Intake, Hard. Carmen Lowry at Melton Hill Dam. Clear the dead from the dam intake to bring power to the lab.
The First Dose, Hard. Monique at Oak Ridge Lab. Make the first doses while Lifeline closes in.
Monique Whitlock, former Lifeline nurse, 31. Warm, funny, stubborn and brave. Her mother, father and younger sister live on the Lifeline campus in Atlanta, and she has not seen them in a year. She travels with the players for most of the road.
Nolan Price, Lifeline Retrieval leader who hunts Monique. He answers to Ruth Keller.
Rudy Salcedo, old Mutated railroad man at Barstow.
Teresa Baca, ice cutter at Bandera Ice Cave.
Lorraine Pike and her son Travis Pike, meat packers of Amarillo who own the blue cold truck. Travis owes Lifeline for a Booster Shot that saved his daughter Maisie, and he sells the party out.
Odell Freeman, Mutated river boatman of the Marked.
Dr. Carmen Lowry, leader of the old lab workers at Melton Hill Dam.
Major Dean Colter, Continuity Command officer at Hoover Dam who reports what he hears to General Carla Nash.
Keep the cooler at the center of every leg. It stays cold for about three days on fresh ice. Count the days, and let the players choose between a fast dangerous road and a slow safe one. The story works best when the players care about Monique before they learn what is in the cooler.
After The First Dose, Monique wants to go home to Atlanta, a few days south of Oak Ridge. Atlanta is also the home of Lifeline, so going home is a danger of its own. The players can choose to take her there.