Trapped underground after an explosion, can Ben, Harry, William and Sally find a way out of this devilish place or will it be their last resting place. Worsdale Mine in Yorkshire owned by Lord Greenbarugh employed 350 men, women, boys and girls some as young as 7 years of age. The mine only some 240 yards deep, being entirely lit by candles was not considered dangerous because it was well ventilated naturally by air being drawn into the mine through number '2' shaft which had no headgear and was situated on the hill 500yards from the main number '1' shaft. The miners were lowered underground by means of a cage suspended by ropes over the headgear and powered by a horse gin. At the time of the disaster there were approximately 150 workers underground.