While the Riders prepare to take out a zone generator that is blocking San Francisco harbor, Bandit infiltrates their base and tricks Hiro into accepting a hypnotic device disguised as a holographic computer game.
The Zone Riders rescue King Donovan, a retired military pilot and Dirk's former CO, as he is being pursued out of the zone. He has details on an Overlord plot to increase the size of the zone by hooking a generator up to the Hoover Dam, and a plan to stop it. But instead of allowing them to sneak up on the generator, the suggested rout leads the Raiders into an ambush, and King ends up suspected of treason.
A girl named Carol Ward is discovered who is immune to Zone bacteria, and both sides race to find out why.
A cargo plane en route to M.C.C. carrying the world's last supply of Neutron-90 is shot down by Overlord over the New York Zone. Now, it's up to the Zone Riders to recover the Neutron-90 (and the pilot of the cargo plane) before Overlord finds it and creates a weapon that would render the existing Zone Riders' suits useless.
While investigating Black Widow activity in Australia, the Zone Riders' equipment is destroyed by an electromagnetic pulse. They are forced to find a way to survive and contact help without their futuristic weapons.
The Black Widows slips a miniature zone pod into McFarlands clothes, activating it inside the MCC while the Zone Riders are on a mission. Forced to go up against their own defenses and Overlord at the same time, the Riders have one hour to take out the pod before a UN ordered air strike reduces the place to rubble.
The Zone Riders bring a scientist to Miami, looking for a possible cure to the zone bacteria in the form of a local plant. Dirk also hopes to find an old friend who was in the area during the zone attack.
The Zone Riders take rocket fuel to a NASA base in order to enable a recon satellite to launch past Overlord's gun emplacements.
The extreme weather is slowly flooding San Juan, while making airborne evacuation impossible. The only route of escape is through the zone, but can the Riders take out the generator in time?
An unactivated zone generator, found in Katerina's hometown, could provide the first and only opportunity to study the zone release mechanism. Well aware of this, Overlord is determined to keep it out of the Riders hands.
In Australia, the Zone Riders capture Bandit while destroying a zone generator. Escaping after a plane crash, Bandit hunts Dirk Courage on a remote island in order to extract revenge for his brother, whom he blames Courage for his death in the Desert Wars.
The Black Widows kidnap U.S. President Greg Rogers and a disguised Bandit takes his place.
Two children searching for their parents location at the Midwest Phone Company inadvertently hack into Overlord's database.
In this episode we discover Overlord's romantic side. The Zone Raides find the woman he was in love before he entered the take-over-the-world business. Using her as bait the riders set a trap to capture the leader of the Black Widows. Dashing out of the Zone in shining armour Overlord goes to rescue his love, but he doen't have only romance in mind.
The Black Widows capture and zone a major oil refinery. The Zone Riders team up with new allies; led by a soldier Dirk Courage fought against in the Desert Wars.
A train carrying scientists reseaching the Spiral Zone to a conference is routed by the Black Widows into the Zone. The Zone Riders are dispatched to stop the train from reaching a power plant within the zone; however things go from bad to worse when Tank's suit fails and he becomes a Zoner and is ordered by Dutchess Dire to stop his colleagues.
Razorback is captured when the Black Widows try to disrupt M.C.C. field studies. He is sent to Black hills prison where he recruits the inmates to his cause. Courage sends Max to infiltrate the prison in order to discover Razorback's plan.
Overlord is captured; both the Black Widows and the United Nations squabble over the future of their organizations.
Katerina is stranded in the zone. She discovers a group of construction workers, outside the influence of the zone, marooned atop Gateway Tower.
Overlord recovers a rocket engine from the original zone shuttle launch. The Zone Riders attempt to stop him before he gains access to a back up shuttle in New Jersey.
A strange yellow mist penetrates the Zone Riders suits rendering them vulnerable to zone bacteria. The Black Widows and M.C.C. seek to discover the nature of the mist.
Overlord plans to destroy the Panama Canal with a ship full of explosives.
Overlord blackmails Jade Scorpion; a Hong Kong river pirate, in order to distribute zone pods along the coast of southern China.
An unwitting king, with ties to Duchess Dire, is placed on the English throne.
Zoned samurai, led by Hiro's sensei, are operating outside the boundaries of the zone. The Black Widows and Zone Riders seek information on how this is possible.
Overlord zones a green beret detachment on maneuvers in the Philippines. The Black Widows team up with the green berets to eliminate the Zone Riders.
A Russian scientist, Dr. Starokof, develops Spirovax; an injection which allows unprotected individuals to enter the zone. The doctor and the Zone Riders attempt to test the formula.
Overlord distills zone spores to create a spore formula. The formula is added to a local water supply making those who drink it enter the nearest zone.
A lab assistant, Ben Davis Franklin, is chosen as a new Zone Rider, but high command decides to give his suit to an Australian soldier named Ned Tucker. Without permission Franklin creates another new suit and covertly follows the Zone Riders on a dangerous mission.
Commander Courage, thinking that the Zone Riders' efforts are not enough, enters alone the NY Zone without protection suit, in order to get zoned and captured. A tiny transmitter attached to his neck enables MCC to keep track of him, and as soon as he is brought to Overlord's headquarters - MCC will transmit him a command, in Overlord's voice, to destroy the zone generator, allowing the UN forces to enter NY and attack Overlord. Unfortunately, as Courage is captured, the transmitter malfunctions. Will the Zone Riders manage to rescue their commander?
The Zone Riders head to Chicago to destroy the Zone Generator that's plaguing the whole city. Max is extra motivated to win this battle as his mother, father and sister are trapped in this particular area. The situation is complicated by the fact that M.C.C. is relying on shady mob gangsters within Chicago to help them get supplies to the United Nations via train.
M.C.C. receives a distress call about a Zone - that is MOVING and growing in size. The Zone Riders investigate to find that Overlord has created a gigantic vehicle that moves over all terrain and drops Zone pods in it's wake. Can the Zone Riders destroy Overlord's Behemoth before he zones the entire world?
M.C.C is shocked to discover that one of their most promising Zone Rider trainees, Barry, is actually the long lost son of Overlord. Barry is kicked out of the trainee program because of this and Overlord convinces him to steal one of the Zone Riders' Neutron-90 suits to get back at M.C.C. But Tank, one of Barry's strongest supporters, is not convinced that Barry's birth records are telling the whole truth.
Reporter interviews the Zone Riders to find out their definition of heroism, and flashbacks tell their stories.
The UN security council is dissatisfied with the performance of the Zone Riders, of two reasons: first, several months passed since the team was formed - but the Spiral Zone is strong as ever; second, the council has received reports about seemingly-questionable command decisions made by Commander Courage, suggesting that the problem is poor leadership of the Zone Riders. Thus Commander Courage is called before special UN committee to explain his conduct as the team leader.