Pilot Jake returns to Jericho after a long absence to claim a sum of money his grandfather put aside for him. With the past five years of his life shrouded in secrecy, Jake evades questions about his whereabouts. As he heads out of Jericho bound for San Diego, Jake witnesses a nuclear explosion on the horizon, an event which instantly changes the lives of everyone. As the town faces a potentially deadly crisis, Jericho's usually sensible people become paranoid, personal agendas take over and well-kept secrets threaten to be revealed, while others will find an inner strength they never knew they had and the most unlikely heroes will emerge.
Fallout With only an hour before the fallout from the nuclear blast in Denver hits Jericho, Jake rushes to get the townspeople inside and away from the rain so that they won't get radiation poisoning. When they find that the official shelter is in disrepair and unusable, they have to come up with other protection fast. Meanwhile, Emily and Bonnie are held hostage by two men posing as police officers.
Four Horsemen Jake organizes a group to gather more information about the explosions after a satellite television in the local bar broadcasts a signal from an Asian news program shows the extent of the nuclear attacks. In addition to the television broadcast, Stanley, who is hospitalized for radiation poisoning, claims to have seen tanks headed toward Denver. With Jericho still cut off from communication and the people craving information, Jake recommends sending four search parties out in different directions to get a sense of what is going on outside of town. Meanwhile, when one of the inhabitants of the mine seeking shelter during the fallout dies unexpectedly, Heather questions the cause of his death.
The Walls Of Jericho When Jake and Heather locate a stranger on the side of the road who is sick and disfigured from radiation poisoning, they must decide whether to help him and risk contamination or do nothing and allow him to die. After they decide to help the stranger and take him to the hospital, Jake and Hawkins sit vigil in the hopes that he will be able to give them information about what's going on outside of Jericho. Meanwhile, when the generator at the hospital is low on gas and supplies in town begin to dwindle, the police must ask disgruntled and panicked townspeople to siphon gas from their cars.
Federal Response The people of Jericho receive a pre-recorded phone call from Homeland Security telling them that help is on the way. The townspeople start to think that life might be returning to normal when the power and phones return. Their hope is dashed, however, after the power surges and electrical lines go down, causing fires to break out all over town. While, Jake and Hawkins work together to fight the fires, they discover that neither one of them is who they claim to be. Meanwhile, still desperate for information, the townspeople vigilantly watch the satellite television in Mary's bar with the hope that another signal will come through.
9:02 An electromagnetic pulse fries everything with a circuit board at 9:02 p.m., plunging the town into darkness. Before the power goes out, the citizens of Jericho watch as minutemen missiles are launched into the sky. One by one, the townspeople receive phone messages alerting them that the Federal government has been shut down and that everyone is under local or state jurisdiction. For the first time since the explosion, people realize they are on their own and must be responsible for maintaining law and order in their town. Meanwhile, Allison, Hawkin's daughter, starts to question her father's motive for moving to Jericho.
Long Live The Mayor While the town prepares to celebrate Halloween, Gray Anderson returns after traveling outside of town and reports back on the horrific things he saw while he was away. Upon his return, Gray is able to provide more information about which cities were hit by bombs and which cities have not been affected. Having witnessed unspeakable terror, Gray is determined to protect the citizens of Jericho from danger. To this end, he wants to interrogate all the new families who came to town before or after the attacks -- including Rob Hawkins. Meanwhile, Jake tries to negotiate with Jonah Prowse, who came back to town to retrieve a member of his gang who was arrested for stealing horses and food. Also, while overseeing Halloween preparations for the town, Emily tells Heather a bit more about her former relationship with Jake.
Rogue River Mayor Johnston's life hangs in the balance when he comes down with a bad case of the flu and it is up to Jake and Eric to save him by traveling to another town to get the medicine he desperately needs. While traveling to Rogue River, Jake and Eric get a glimpse of what's gone on in the surrounding areas and discover that, since the explosions took place, the world outside of Jericho has changed immensely. Meanwhile, Gray questions the Hawkins family about their mysterious arrival.
Crossroads When Jericho receives a surprise visit from several seedy out-of-towners, the residents realize they need a plan to keep intruders out. Emotions run high when the townspeople meet to discuss ideas for securing their borders. One solution that strikes a nerve with several citizens involves a strategy that would isolate a large part of the town from the other. Meanwhile, Emily wakes up on the day she was supposed to get married and imagines how her wedding day would have gone if Roger was still there.
Red Flag As bombers fly over Jericho dropping parachutes with palettes of supplies attached, citizens are both thrilled and cautious about their much-needed relief. As the citizens scramble to retrieve the food and supplies that are dropped from the sky, Mayor Green tries to convince them to wait until everything is tested to prove that they are safe. Meanwhile, Jonah attempts to commandeer two of the palettes for himself.
Vox Populi When one of Jericho's own turns up dead, Gray organizes a manhunt for Jonah, against the wishes of Mayor Green. As the mayoral election nears, Gray seizes the opportunity to show his strength as a leader when one of Jericho's citizens turns up dead. Gray is convinced he knows who committed the crime and launches a manhunt to capture Jonah and restore peace to Jericho. Meanwhile, as playful reminiscing continues to heat up between Jake and Emily, both are hit with a curve ball when an unlikely face returns to Jericho.
Return To Jericho From the powerful premiere episode that saw the town of Jericho living with the fallout of a nuclear attack, to the discovery that someone from outside of Jericho was coming to visit Hawkins, to the unexpected return of Ashley's fiance, Roger, catch up on everything that took place during the first 11 episodes.
The Day Before Parts of Jake and Hawkins' pasts are revealed during a flashback to 36 hours before the bombs went off. The day before the explosions, Jake is in San Diego trying unsuccessfully to make an honest living, while Hawkins' mysterious past is furthered by his association with a woman named Sarah. Also, Emily's fiance, Roger, heads to Chicago for a job interview that Emily is not happy about. Meanwhile, in the present day, refugees including Roger and Sarah arrive in Jericho bringing more questions with them.
Black Jack As winter approaches, Jake and Johnston are joined by Dale and Heather on a trip to a trading post several hours outside of town in search of equipment to fix the local windmill. Heather knows how to fix the local windmills if she has the necessary equipment and convinces Jake and Johnston to travel with her to "Black Jack," a trading post several hours outside of town. Against Johnston's wishes, Dale joins them in hopes of trading supplies from the market for something the town can actually use. Meanwhile, much to the dismay of his family, Hawkins brings Sarah back to their home as they both try to figure out who is watching Hawkins.
Heart Of Winter Jake, Stanley and Mimi find themselves fighting for their lives when they run into several dangerous strangers on a hunting trip. While traveling outside the city limits in search of wild game, a truck pushes the truck that Jake, Stanley and Mimi are driving off the road, leaving Stanley unconscious and Jake pinned underneath the vehicle. Mimi realizes that she is their only chance of survival and heads back to Jericho on foot. Meanwhile, Hawkins discovers that he has put his family in grave danger, and Emily and Roger continue trying to rebuild their relationship.
Semper Fidelis With the arrival of the Marines, the citizens of Jericho consider what their lives will be like when law and order is restored and the nation begins to recover from the bombings.
Winter's End Faced with a catastrophic complication in April's pregnancy, Jake forces Kenchy to confront his post-traumatic stress syndrome and perform a heroic operation.
One Man's Terrorist Gray's decision to kick the refugees out of Jericho sends Roger off the deep end.
A.K.A. Jake confronts Hawkins when he discovers that Hawkins might not have been completely honest about his background before arriving in Jericho.
Casus Belli When Eric doesn't return from New Bern with the other men, Jake senses something is wrong and uncovers what their neighbors secretly have in store for the citizens of Jericho.
One If By Land The tension between Jericho and the neighboring town of New Bern escalates when several people are shot and injured while trying to steal from Jericho's salt mine.
Coalition Of The Willing When the town of New Bern begins bombing the streets of Jericho with mortars, Mayor Gray Anderson is faced with the decision to fight their formidable opponents or surrender in order to save lives.
Why We Fight Johnston leads a heavily outnumbered army of citizens from Jericho into battle against New Bern, where one of Jericho's own will be lost during this fight for survival.