Tonight is a big night for the London Underground line that used to be known colloquially as "The Misery Line" - the Northern Line is joining the Night Tube from tonight.
The line - which will only operate overnight on Fridays and Saturdays - is the fourth to join the service, following the Victoria, Central and Jubilee Lines. The Piccadilly Line will complete the set of planned launches on December 18th, just in time for Christmas.
So you can probably expect to see Mayor Sadiq Khan getting his photo taken with revellers if you're in the vicinity of Leicester Square tonight, but be careful not to stay out late in the City of London, as the new service will only be covering the Charing Cross branch of the line, on the basis that the City is basically deserted at the weekend.
According to Transport for London, if you head down to the Tube tonight you can expect a train every eight minutes between Morden and Camden Town - and then a train every 15 minutes if you're going further north. The tiny Mill Hill East spur on the High Barnet Branch will be getting nothing - so you'll still have to ge the night bus or shell out for a cab.