Arimathea Artefact was the code name for a top secret object believed to have magical powers. Whether it was meant as a nuclear device or a primary trigger is unknown. Its function was to serve as a focal point. The The Golgotha Project set the item off whilst using detectors that would not hit the market for decades. It took three years to prepare the grounds. When they did set it off, it created a rift and went haywire. According to the readouts, another rift from another point had opend up and created a bright light. It was said to have made those who watched fearful and seemed to harbour "the negation of life."
Bomber planes were sent to bomb the event lest the rifts engulf the world. The men later returned to the globe and found that the earth had, forming a crater, and that there was an unidentified substance at the bottom, which the men refused to touch, for fear of ruining reality.
The men recruited the Fourth Doctor to help them. (PDA: Heart of TARDIS)