The Olympic torch neared the end of its 7,000-mile (12,900-kilometre) journey around the British Isles on Friday, completing a trip down the River Thames to Tower Bridge on board the Royal barge Gloriana.
It is now seclusion at City Hall before appearing at the opening ceremony to light the Olympic cauldron.
The identity of the cauldron-lighter, and the way in which it will be done, is the ceremony's most closely guarded secret.
It will be the climax of director Danny Boyle's extravaganza, which is titled "Isles of Wonder" and features 10,000 performers.
A panorama of Britain's past, present and future, the opening ceremony will be seen by 60,000 spectators inside the stadium and a global television audience estimated at one (b) billion.