Mono Monday143: The Third Man .

In this case wears black :------
On leaving the courtyard this morning I noticed two workmen way up on scaffolding looking though plastic sheeting at something or someone down below. Whilst getting my camera ready to zoom a third man came and joined them He's the middle one , in black.. They seemed transfixed . So was I since no mono setting was needed for this . .It had to be a Mono Monday Blip .Then I discovered the challenge twist,' the third man.'... The man in black arrived last .   Even  now I've no idea what they were watching .