First there were the big squares of plywood, bordered with yellow and black tape. Then, yesterday afternoon, they arrived in their yellow helmets. Three foot long drill bits. The mysterious squares pulled up to reveal the concrete secrets below...

The squad of art-builders were preparing the way for the Big 4. Is it landing this weekend? A closely guarded secret. Even those in the know don't really know. Rumour has it Westminster Council don't want the work going on on the weekend - some major engineering going on on the premises with cranes and steel girders and 800 staff coming&going makes much more sense.

So will the Big 4 be there when we arrive on Monday? Watch this space and I'll watch that one for you...