We're all of a-quiver.
Trains for the Mail Rail — London's (now not-so) secret Post Office railway — are being test-driven beneath your very feet (if you're reading this in Mount Pleasant).
The subterranean track — formerly used to shuttle post from one London sorting office to another — opens to the public in mid-2017, as part of a new Royal Mail visitor attraction.
Here's a video the ride you can expect:
This view, however, doesn't give the completed experience which, we're told, will involve a dose of interactivity.
The network, which opened in 1927 and closed in 2003, runs from Whitechapel to Paddington, criss-crossing the tube network. Although only a section of the track will be accessible to the public, it's still on course to become one of the most mouth watering attractions for London in recent times. Because: little trains. Underground.
Fresh stock was lowered into the tunnels in November 2016, for the first time in four decades. Like this:
And just because we're so bloody ruddy excited, here's another POV shot:
Almost makes you want to start sending letters again, doesn't it?