### Clue: Universal beginning and end for 1 across 12 (3,4)
### Answer: BIG BANG 
 ### Explanation: Definition: Universal beginning,end for 1 across 12
  Double defn:  1st: Start,beginning of the universe about 14 billion years ago; and 2nd: End of a lot of regulations (ie. deregulation) in the London financial industry, symbolised by 1 across 12 "trading floor" a mere 25 years ago, a Thatcherite reform