X--未知的元素

British Army radiation drills at a remote Scottish base attract a subterranean, radioactive entity of unknown nature that vanishes, leaving two severely radiation-burned soldiers... and a &quotbottomless&quot crack in the earth. Others who meet the thing in the night suffer likewise, and with increasing severity it seems to be able to &quotabsorb&quot radiation from any source, growing bigger and bigger. What is it?? How do you destroy a thing that &quotfeeds&quot on energy?