The story starts in the middle with Muzetti, Cranfield, Baransky, and B.B. Mitchell appearing in the midst of a 16th century siege of a meso-American fort. The D66 team joins a group of Spaniards with their Chichimec indian allies who are surrounding the fort, hiding in arroyos to avoid the atlatl-assisted spears and arrows of the enemy. Inside the fort, what are apparently time-traveling nazis help to defend with machine guns, while some kind of great fire magic is at work inside. Laszlo sees a cherry-red glow of a cigarette on the wall, and hears the voice of the C.W. Kern. The smell of burning chilis fills the air, and a bright strange star (Aldebaran) is in the sky.

A pair of strangely clothed figures appear in the middle of the battlefield and are gunned down by the machine gun- the gunner knew where to shoot before they appeared. The D66 agents make a rush to retrieve the bodies and the strange device they carry. The guns they brought don't work, and so they try to use makeshift flash bombs and the Spanish cannon to lay cover fire. The bodies are of an Asian woman and a white male, in strange clothes. They look familiar to us (from the attack on Nathan Eisenhower). They have the same futuristic needle-throwing pistols and several grenade-like objects each. The device they had is a metal cone-shaped object with odd handles and a button.

A disorienting timequake hits and the D66 agents are yanked out of this place.

In the DET66 Brownstone at 1444 K St. NW, numerous agents are relaxing while a few- Doon-Green, Kieyoomia, Lubelsky, & Skoble- interview with the Holt sisters, two young negro girls who claim to be able to speak with spirits. They say they can only speak to one particular spirit, who apparently looks like the devil and who they call "Mr. Splitfoot". Lubelsky's ghost companion, Captain Koszinski, indicates they're telling the truth, but warns Lubelsky when they start chanting that its a bad thing.

Just as Doon-Green is going to get assistance, they all hear an explosion deep in the building. Running toward the stairs, Doon-Green and Skoble are gunned down by strange automatons with bullets in their fingers.

Elsewhere in the building, agent Kessel is apparently killed by his proximity to the explosion, eminating from the cellar (where the decanted head of Felipe Espinoza was stored). Agents Hoffman and MacGruder moved with superhuman ability to fight the robot attackers and begin rescuing folks from the burning building. Kieyoomia and Lubelsky wrestled with one automaton, but were unable to stop him before he shot and killed Administrative Director Olsen. The attack is finished, the building burned, and several agents are dead. It is determined that Kern and his AsA are behind the attack, and that the magic clockwork robots are the work of Von Hohenleutner.

D66 Agents Muzetti, Baransky, Cranfield, and B.B. Mitchell, who were not present at the attack on the brownstone, meet with OSS director Donovan. Donovan is clearly shaken by the attack, and tells them that they must go to New Mexico and track down the origins of the head in the jar (Espinoza). Donovan gives Cranfield a letter, to be given back to him "the next time you see me". Upset about the attack, and confused about why they're going to Mexico, they draw equipment and get on a train.

Several civilians meet the same man in a public square for different reasons. A shoe-shine named "Joe Bernard" (Steve), a lawyer named "Dick Shafely" (Joel), a Quaker pacifist called (oddly enough) "Skip Bradford" (Scott), and "Nicholas Crawford" (Dale) encounter Judge Joseph Crater, who tells them about the "river of time", the ripples that are caused in it by careless people, and the aztec warriors who are about to appear and attack them. The civilians are naturally incredulous. Nonetheless, when the Aztecs attack, they readily take his time-hook necklaces and grab onto him and he transports away from there.

The four agents sent by Donovan (Muzetti, Cranfield, Baransky, and Mitchell) arrive by train and soon encounter "Project Rainbow" coordinator Robert Heinlein. He has a train car full of of equipment from his project and orders more vague than the agents' own. They help him get a truck and transfer the gear to the only available warehouse space in the small town.

The agents investigate "Tobin's Arms", the bar in which the decanted head was known to have been kept 20 years ago. Magnolia Jensen is the current owner, and she knows of the head only as history. After some discussion, they learn from her that the Navajo considered the local valley to be "the opening to 'Sipapu', the otherwordly underground whence came the indians in the first place, after being cared for by 'ant people' during the time of evil skies."

The agents rent rooms but spend the night helping Heinlein set up his equipment. The warehouse has, strangely enough, an amazing power connection to the local power company ("Donovan Electric"). It also has a ritual magic circle drawn on the floor, which Muzetti promptly destroys. A scrap of burned calendar indicates the date "march 2, 1869". Baransky paints some abstract artwork on one wall of the warehouse to relieve stress.

By 9 pm the next evening, the agents have learned that someone (C.W. Kern?) had been here before them. Four arrived by car, two left. Assuming they've used magic to go into the past, the agents telegraph to Washington for orders and are told to go into the past and stop the nazis.

Just before the agents jump, a strange "timequake" hits them, leaving them disoriented. Several strange and malicious fire creatures appear, floating in the air. The agents fight them off as Heinlein runs (and is hit by one), and then they jump through the Rainbow device, equipped only with silver jumpsuits.

The four time-traveling D66 agents encounter a crashed biplane, and its pilot, B. D. Foulois. The pilot, clearly hurt, talks to them about when and where they are, and makes reference to General Pershing and Pancho Villa. Baransky takes his gun, Muzetti gets cigarettes from him, while Mitchell tries to give him first aid.

Unexpectedly, a time wave hits and drags the agents from this point in time.

The four time-traveling D66 agents arrive sick and disoriented, and are quickly overcome by others (primarily Sheriff Tom Tobin, who killed Felipe Espinoza in the first place) who were waiting for them. They are arrested, stripped, and confined. Baransky's gun, stolen from the pilot Foulois, is useless.

The four time-traveling D66 agents arrive near the warehouse where they first began their time-jaunt. They have been to "the Plain of Jars" siege and are carrying the futuristic weapons and the odd cone-shaped device.

They see a movie poster indicating the date and advertising a strange film, "El Topo", with midgets and cactus-flayed priests. The agents are stunned by a thundering sound and a fast-moving aircraft far overhead. They are then approached by a man identifying himself as a movie director called Alejandro Jodorowsky. He thinks they are extras and berates them for being late. Baransky looks inside the warehouse and notices his artistry still visible on one wall.

Mitchell gives in to the directors demands to see the cone-shaped device just before a timequake hits and sweeps the agents away (without the device).

The time-shifting agents return to the siege in 16th century meso-america without the cone-shaped device. Kern calls from the fort wall for parlay with Baransky. As they speak, Baransky realizes that behind Kern stands his dead lover, Sarolta, very much alive. Kern says that he plucked her from her past, a year before her death, and will trade her life for the futuristic cone-shaped device. Baransky's balanced world view is shaken.

The four civilians plucked from their own time by Judge Crater arrive here in the bushes near Columbus. Crater explains that he is with an agency called the "time patrol" that protects the integrity of the timeline. He goes on to say that they are all alternate versions of four time-traveling agents who have been arrested and detained here. He insists that it's "all very complicated" and explains that the four of them must break their doubles out and work with them to protect Dwight D. Eisenhower's grandfather from the nazis and save the timeline. This means little to them, as the nazis and Germany are good people in their own alternate timeline and Eisenhower is nobody.

Crater gives them futuristic "needler" pistols, demonstrating their effectiveness on a cactus.

The four alternate-timeline versions of the D66 agents Baransky, Muzetti, Mitchell, and Cranfield stand with Judge Joseph Crater of the Time Patrol just outside of the ranch at Columbus. They are spotted while making plans and approached by Coppermine Lemon, a cool dude.

Taking pity on the badly-dressed easterners in the desert sun, Lemon invites them into the ranch. They had asked about Eisenhower, and so while they rest by the well, young Nathan Eisenhower comes to them. He is 16, and strapping dual pearl-handled pistols. The would-be agents offer him a prize winning if he would leave with them, which he wouldn't. In short order, the nazis arrive and the gunfight is on.

Additional characters are introduced- "Jumpy" the fat drunk; "Screech" the ranch cook; and "the Uruguay Kid", a gaucho. the civilians do their best, but Eisenhower is wounded and Judge Crater is killed by WWII nazi machine gun fire. Two additional Time Patrol agents arrive- an asian woman and a caucasian man.

In the firefight, several nazis are killed, as is the Uruguay Kid. The D66 agents are freed, and Baransky promptly takes the needler gun of his rescuer (his alternate self, Bernard) and initimidates him for his clothes and information as to how they came to be here. The Time Patrol agents quickly give them time-hook necklaces and a time-puck button set for 1916.

In the end, Eisenhower is saved from the nazis and the D66 agents have just enough time to put some clothing on before a timequake hits and sweeps them away.

The four time-traveling D66 agents arrive near the movie studio/warehouse again for the first time. They see an odd movie poster indicating the year, and find a bunch of drugged out youths the studio. Baransky finds the remains of his artwork still on the warehouse wall. Muzetti, dressed on in a horse-blanket poncho and a hat, gets a smoke from a hippie girl.

An actor named Ernest Borgnine is there, and takes an interest in the agents. He listens to their planning and thinks its a script. They get some more clothes and Baransky takes some (prop) pistols.

Another timequake hits and sweeps them to another place.

The four time-traveling D66 agents contemplate the bargain that C.W. Kern has made- the futuristic cone-shaped device for Baransky's lover, Sarolta. Searching the bodies of the Time Patrol agents again, they find another time-puck device set for 1972. Fighting indecision, they latch onto one another as instructed and press the button on the 1916 time-puck they'd been given.

The time-traveling agents appear in the dark near a camp of Federal soldiers on the outskirts of Columbus. The agents spot a large pile of dead bodies nearby, and determine them to be Mexicans. Arguing in the dark, the agents are spotted by soldiers and stopped. Shortly they meet Lt. Patton, who orders the agents taken into custody.

Shortly, General "Black Jack" Pershing comes to talk to the characters. He makes it known that he knows who they are, and why they've come. He implies that he is friendly with Kern's people and that he was warned about the D66 agents. He intends to hold them for a time, and then ship them out and away from his operation.

In a holding cell, they meet a Lt. Bill Donovan, a younger version of the OSS director. Cranfield gives him a letter, which was apparently given to him for just this situation by the future Donovan. This is enough to convince the current Donovan to help the agents get the decanted head of Espinoza and escape. He gives them horses from the 10th cavalry (Buffalo Soldiers) to ride off on.

In the desert, they are met by a soldier of Pancho Villa, who escorts them to Villa's camp. There they meet Villa and two gringos by the names Ambrose Bierce and Everett Jamison (an englishman).

Jamison tells us that he knew of our arrival from talking to some other agents (the Time Patrol). Jamison also seems to be aware that Pershing is up to no good in Columbus, and cites the history of fire in Pershing's background and the magical nature of the area around Columbus (built on the "Plain of Jars").

When the D66 agents mention the name "Kern", Jamison jumps. Interrogation leads them to realize that Jamison is a younger, untainted version of Kern, living under an assumed name to escape the evil.

The agents consider shooting him then and there, and spend much time deliberating, but finally settle on kidnapping him to 1972. They hit the button on the time-puck

Arriving two days after their first visit to this timeline, the D66 agents return to the 1972 movie studio. Looking for Alejandro and the cone-shaped device, they have to wait for several hours until he returns from his weed-buying trip into Mexico. When he returns, Mitchell uses the threat of the law to produce the futuristic device. Mitchell messes with it some, pulling the levers, but is prevented from pushing the final button by a timequake.

Returning to the siege apparently after an attack, the D66 agents realize they have appeared in the "kill zone" and promptly drop a smoke bomb. They spot and search the last of the Time Patrol bodies, retrieving a time-puck set for 1944 and a time-hook necklace.

Bradford impulsively pushes the final button on the cone-shaped device, at which time a small red light begins flashing. Muzetti starts yelling at the wall to Kern to parlay, which yields a volley of indian arrows.

Shortly, bargaining with Kern begins. The agents try to intimidate Kern with the decanted head (he doesn't care) and then with the fact that they have his younger self with them, and therefore the key to wiping him out of existence. They make it known that they have the cone-shaped device, and he sends out Sarolta. She is under a spell and afraid to let us touch her, but the agents throw her a time-hook necklace and the time-puck for 1972. While Kern tells her not to do it, Baransky says to "go- I'll find you" and she hits the button. Kern, enraged, tells Jan Lang, the metahuman nazi, to gun them down, but Baransky shoots the needler at his head. the older, evil Kern disappears, but a few agents see his foot-tracks in the sand. Muzetti calls them together and activates the 1944 time puck as the cone-shaped device- now clearly a powerful and active bomb- nears explosion. At the last moment, Muzetti feels another touch on his leg before they are swept through time.

The D66 agents arrive with the young Kern near the warehouse. It is days later than when they left, and the building is a burned out hulk. All of the Project Rainbow equipment is trashed and Heinlein is gone. Muzetti begins making noise about the elder Kern having "turned invisible" and come along on the trip back, but they are unable to locate him before the younger Kern is knifed in the back. They scramble, but do not find the elder Kern.

In the final analysis, the attack on D66 was averted by the fact that these four agents stole the head of Felipe Espinoza out of the timeline. In addition, they averted the unleashing of unholy evils upon the world in general by detonating the Time Patrols Neutron bomb at the "Plain of jars". This destroyed Kern's attempts to summon up "Cthugha", an eldritch horror.

Sarolta Jemnitz is now theoretically alive and well in 1972, and Laszlo Baransky is determined to find her again. Both Muzetti and the younger Kern require medical attention. The four agents, Sarolta, and the two versions of Kern are the only ones who know about these events that have transpired across time.