It happened once. It happened again.

While we were visiting several customers in Europe, we went to visit one of our customers that always requests for deeper and better assessments on their networks and plans. A large multinational corporation, last year we managed to get their marketing plans after blending in with their marketing staff.  
This year, the security director asked us to try to penetrate the Board of Director's meeting. Like last year, blending in proved to be a good tactic.

Sometimes you don't know what you agree to until it's too late. In this particular project we were testing physical security around the customer's building. The customer asked us to try to bypass their physical security measures and if possible reach a certain room and leave a note there.

It sounded like a fun project.

The next 3 weeks were spent researching the target, recon during the day and night, trying to get the right names for some social engineering attack if needed and gear, techniques and planning.  

At the end we discovered a vulnerability and we thought we could exploit to get us in. The only problem was that in order to get that potential point of entry we needed to get to the roof.