The player controls PRISM, the world's first sentient computer, in the year 2031. The economy of the United States of North America (USNA) is failing. Great numbers of youths are turning to "Joybooths" (a device which directly stimulates the sensory input of the brain) and committing suicide by overstimulation. A new arms race involving nuclear weapons no larger than the size of a common pack of cigarettes threatens to turn the USNA into a police state. Unaware that it is a sophisticated computer, PRISM has been living for 11 years (in real-time, 20 years within the simulation) as an ordinary human, "Perry Simm." Dr. Abraham Perelman, PRISM's "father", informs Perry of his true nature and gently brings him from simulation mode into reality. Perelman explains that he has awakened PRISM so a vital mission can be performed: running a simulation of a revitalization plan (dubbed the Plan for Renewed National Purpose), sponsored by Senator Richard Ryder. The plan calls for "renewed national purpose" through de-regulation of government and industry, military conscription, a unilateral approach to diplomatic relations, trade protectionism, and a return to traditional and fundamental values. While in simulation mode, Perry is able to record experiences in a buffer which will be analyzed to evaluate the success of the plan. If Perry "dies" in the simulation, it is not catastrophic; the simulation can simply be reset and reentered.
Note: The following description is based on the player making the correct choices and successfully completing the game.
The simulation initially focuses on the fictional small town of Rockvil, South Dakota, 10 years after the plan has been implemented. Given a list of public, civil, and private areas to record for evaluation, Perry enters the simulation to find a revitalized Rockvil in 2041. The government is more efficient, the economy has improved, food is plentiful, and his simulated wife (Jill) and son (Mitchell) are hopeful for the future. When the recordings are brought back and evaluated, the plan is deemed viable and preparations to implement it are begun.
Perelman, however, feels uneasy recommending such a sweeping plan based on relatively little data. He is also distrustful of the plan. (When PRISM asks Perelman about himself, Perelman mentions that politically, he has "always been pretty liberal...." Conservative elements are considered to be the plan's strongest supporters based on statistical sampling, although the plan has the support of a majority of both liberals and conservatives.) In a passing comment to PRISM, Perelman notes that further simulation might allow more in-depth evaluation of the long-term effects of the plan. With nothing further to do, PRISM enters sleep mode; he has no physical body that requires rest, but since his mind is based on that of a human, sleep is necessary for his mental well-being.
After waking, PRISM finds that the Simulation Controller has correlated enough data from the initial test period to provide a further projection of 20 years into the future. With Dr. Perelman occupied with other concerns, PRISM begins the new simulation. By 2051, Rockvil has begun to decline, as the optimism granted by the plan wanes. Pollution has increased as woodlands are stripped and converted into filthy industrial districts. The Border Security Force, created to defend the nation against Soviet nuclear terrorism, conducts warrantless raids on people seemingly at random, including Perry's family. Capital punishment has been expanded; two defendants are seen facing the death penalty for attempted rape. Due to rising crime, a government-initiated curfew is now in effect. The quality and supply of food dwindles. A new cult, The Church of God's Word, arises and finds many supporters within the increasingly discontented public. Perry quietly records all this and presents it to Perelman for evaluation.
Examining PRISM's recordings, Perelman expresses alarm and cautiously suggests further investigation. Once again, the Simulation Controller has gathered enough information to create another new simulation era, this one 30 years after the plan's implementation. Perry enters to find matters even worse. By 2061 water pollution is nearing catastrophic levels. The BSF and local police treat the public savagely. Public executions of criminals are televised and are extremely popular. Vandalism and cruelty to people and animals alike are rampant. Public services are in disarray. The Church of God's Word has grown to gain a stranglehold on the nation, establishing a caste-like system of social classes and seducing Perry's son Mitchell to abandon his family. Once again, PRISM discreetly records the chaos.
Perelman is deeply disturbed by the recordings, but is acutely aware of the powerful people behind the plan. Exhaustive evidence will be needed to discredit the plan, so he asks PRISM to enter a simulation set 40 years in the future. By 2071, the future is grim indeed. The Church has installed itself as a new totalitarian government. A Church newsletter reveals that higher-echelon Church members are allowed to own slaves. Mitchell, now fully under the Church's power, leads a raid on his parents' home and has Jill arrested for heresy. ("She spake [sic] against the Church," Mitchell charges, "[and] tried to poison the mind of a child too young to know the Truth.") Strict rationing is in effect for the miserable food available; if Perry attempts to use his ration card twice within one day, he is arrested, beaten, and quickly tried and executed. Attempting to enter one of the few food establishments leads to a violent dismissal, since patronage is reserved for Church members. The public executions of the past have given way to bloody gladiatorial matches between condemned criminals. Sudden and random death is frequent: Perry is shot by a drunken officer after curfew, and he is stoned to death in a schoolyard by Church youths, who view the sickly, malnourished Perry as little more than an animal.
These records still aren't quite enough to satisfy Perelman. The doctor feels that there might yet be some small hope for revival, and sends PRISM to the final projection of 2081, 50 years after the implementation of the plan promised to save the nation.
There is no salvation. The environment has been devastated. The small area of Rockvil that can be survived is a wasteland, and society has collapsed into complete chaos. Telephone poles have been chopped down for firewood. Buildings collapse into rubble. Defenseless people are ripped to shreds both by packs of wild dogs and barbaric humans. Barely any recognizable or edible food remains. Perry makes recordings of several brief moments of life cut violently short, and then leaves the hellish projection for good. At last Perelman feels that enough evidence exists to declare the plan a complete disaster. As he prepares to leave and present PRISM's findings to the government, he thanks the computer for its efforts; without them, the nation, and perhaps even the entire world, would have been doomed. Left once again with nothing else to do, PRISM enters Sleep Mode.
The computer "wakes" again hours later to find that the facility where it is housed is under lockdown by the Dakota-Manitoba National Guard. Senator Ryder sees the discrediting of "his" plan as a personal insult. Incensed, he ignores the evidence of its disastrous consequences and decides to make Perelman pay. Ryder bursts into Perelman's office and proceeds to berate him until his implied threats escalate to explicit ones. PRISM surreptitiously begins recording the senator's abuse via an audio/video link. Delivering a final spate of insults and promises of violence, Ryder leaves. PRISM waits for an interface to a global newsfeed to become active so the recorded incident can be transmitted.
Shortly after Ryder storms off, a small craft lands on the building's roof and four men dressed as maintenance workers make their way towards PRISM's maintenance core. They seem suspiciously out of place, especially when they start tinkering with the cooling systems. Realizing that the men are goons of Ryder's, PRISM closes the ventilation to the area; fumes accumulate quickly and render the assailants unconscious. They are soon discovered by the National Guard and arrested, and Ryder's attempts at intimidation are broadcast around the world.
The plan is thoroughly discredited and Senator Ryder is publicly disgraced. Perelman lauds PRISM for the initiative it has shown in recording the incident and in protecting itself from harm. As a reward for the outstanding service it has performed for the nation, PRISM — or rather, Perry — is allowed to "retire" into a final simulation -- a USNA in which a "new" plan based on pacifism and social welfare-statism has been implemented. Perry is reunited with his family in the year 2091; he, his wife and son are happy and prosperous, and Perry looks towards his golden years with joy and anticipation.