While much of London slept last night, a 550-tonne boring machine was being lowered into a 40-metre shaft in Canning Town, the latest milestone in Crossrail's relentless appearance beneath the streets.
The behemoth, christened 'Elizabeth', and her sister 'Victoria' will shortly begin tunnelling towards Canary Wharf (whose station box is ready and waiting) and then through Tower Hamlets to the City, before reaching Farringdon, where they'll have an emotional meet-up with their eastward-tunnelling counterparts Ada and Phyllis. It'll be just like when Phillipe Cozette met Graham Fagg.
More photographs and information (including the obligatory Mayoral burble) on the Crossrail website.
Follow Crossrail's progress on this interactive map.