The film tracks the fictional scientist Dr. Howell, played by Glenn Conroy, as he journeys from his hotel room in London to his laboratory in New York City, and shows how each scenario affects his trip as well as those around him, with numerous experts delivering commentary on that specific disaster as it unfolds.
The following are the disasters shown in the order they happen in the movie:
In this scenario, a volcanic eruption on the island of La Palma prompts an enormous landslide where a large portion of the island collapses into the sea, producing a colossal mega-tsunami to rush across the Atlantic Ocean and strike the east coast of the United States, engulfing most of New York City, but leaving many buildings complete.
This scenario begins with an unexplained 'missile attack' in an isolated area somewhere in the Middle East. The 'missiles' are soon exposed to be small asteroid fragments, the precursor of a much bigger asteroid on an impact course with Earth, threatening Berlin, Germany. The asteroid is found, and an effort is made to change its path using nuclear ICBMs. The attempt fails, resulting in the asteroid breaking into hundreds of smaller pieces, with the largest piece then impacting and destroying Berlin.
In this scenario, a mysterious virus like SARS or influenza is released, wreaking havoc as it spreads at an extraordinary rate through Europe, the United Kingdom, and North America, provoking many countries to decree martial law and close their borders, in a frantic effort to quarantine the spread of the disease; however, they fail, and most of humanity is presumably destroyed by the virus.
This scenario is based on the supervolcano beneath Yellowstone National Park erupting, incinerating everything within 100 km and releasing ash into the atmosphere which is projected to cool the Earth, with the final scene showing a destroyed Denver. This segment has only aired in the UK. This scenario can be found on YouTube.
The only scenario in which Dr. Howell reaches his laboratory unhindered, with people protesting and shouting, "Stop the experiment!" On numerous televisions, several scientists talk about a new type of matter, the strangelet, and just how improbable it is for one to be created. Upon arrival, Howell and his colleagues begin a highly divisive experiment using the world's largest particle accelerator. The experiment rapidly goes out of control, resulting in the creation of a single strangelet. The strangelet first triggers the collider and most of the adjacent area to explode, then rises out of the ground and starts to change the entire planet into strange matter, starting with New York City. The strangelet creates havoc on the Earth's climate, damaging a Boeing 747 before it collides with a Boeing 777 attempting to flee the storm. Everyone onboard both aircraft is killed. Off-screen, the strangelet finishes devouring the planet. This scenario establishes that, by preventing Dr. Howell from reaching his laboratory, the other scenarios ironically saved humanity.