And I have made a discovery, with which I hope to delight you. See below a very small extract of the map, showing the area around Euston and St Pancras.
|The Underground between Euston and St Pancras|
Obviously, I don't need to patronise you. It's obvious, isn't it? If you travel from Euston to Kings Cross/St Pancras on the Victoria line (light blue), you travel North. But if you travel from Kings Cross / St Pancras to Euston on the Northern Line (black) - you travel North.
I can see I will be spending a long night looking at Ordnance Survey maps.