h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

In case anyone didn't know, Mill Hill East was originally planned to be part of a branch that would turn off the High Barnet branch at Finchley Central, go through two Mill Hill stations, join the Edgware branch and terminate 3 stops past Edgware. I think North End (Bull and Bush) may have been the planned point for the Mill Hill branch to join Edgware.
Can anyone clarify?

Sort of wrong - when it was all built in the 1860s as part of the LNER line from Kings Cross, the line came up through Finsbury Park, Highgate, Finchley Central and the main line was supposedly to Edgware (Mill Hill East, The Hale (where Broadway is now) and thru to Edgware) and High Barnet was on a branch.
As the line was taken over by the tube - electrifying and doubling as it went - the plan was to double to Edgware, and continue to Bushey Heath (Watford depending on who you ask) The main obstruction to this was WW2 which stopped the advance at MHE. Passenger service ended sometime later - goods continued until the 60s, and the line was lost (but continues to be a very nice parkland walk round the back of Copthall). No-one really minded b/c there was a perfectly good tube service by now to Edgware.
You can see traces of the old Edgware station around Edgware, it is to the west of the tube, and you can also follow the line on your trusty A-Z, or electronic equivalent.
North End, known as Bull and Bush, was built when the tube, later extended to Edgware, originally opened as far as Golders Green, about 1900. Only the platforms were ever built. It was used for storage in the war. Lots of ghosts live there now.

I would add to that, that if you happen to be walking or driving around the Mill Hill East area you will drive over a number of bridges. If you look underneath, there's nothing except undergrowth. These bridges were to accommodate the line which was to run underneath.