As soon as I have landed in Heathrow, I visit my employer at the US Embassy for a short briefing.
An organization, called ORPHIA, is planning to steal some of the British Crown Jewels. My commission is to replace these with traceable replicas and then deliver them at Traitors Gate, where I will be met by other agents.
I must not kill the guards or leave any traces.
I'm entering the Tower during daytime as an ordinary visitor and cannot bring all my equipment. The rest has been placed in the sewers behind a security door.
The pink line on the model of the Tower shows me approximately where the backpack is placed.