Empty Nest

On the way up towards the outhouse to collect a trug for Mrs SoL, something caught my eye. It slithered. It vanished into the wall of the outhouse. I decided to have a look inside the outhouse as we have nesting redstarts in there. 
Or we did.
Main pic is of the nest, empty. About 5 days ago, there had been at least 3 eggs and a grumpy mum. No sign of eggs or Mrs Redstart who had been so diligent in sitting on the eggs even when I occasionally had to pop in to collect stuff and there it was. On a ledge under the window. A ‘couleuvre jaune et vert’, or western whip tail snake. See extra pic. They are a harmless grass snake, unless you happen to be an egg, or a small bird.
I think we found the culprit.
Mrs SoL is not happy.