There are plans to run Overground to New Cross Gate all Friday and Saturday night from 2017, proving that the tube network does exist south of the river (but only just).

But we do have a very good night bus network, and not just on Friday and Saturdays.

Waterloo to Forest Hill take 54 minutes at 5pm, but it only take 24 minutes at 2am (buses run every 20 minutes). By train the journey from Waterloo takes approx 25 minutes (during the daytime), so during the night the bus is actually faster than the train would be, if it existed!

Despite this excellent bus service at night, I'll continue to ask Overground to find ways to extend their night service to NXG to Crystal Palace, at least until 1:30am.