At Euston the two branches of the Northern Line are approximately at
right angles. The CX branch runs along Eversholt Street, while the Bank
branch takes a large loop, converging with the CX branch just south of
Camden Town. There are then the complex junctions, after which the two
branches follow along the two main roads northwards.

I reworked the area around Camden Town. Also moved Euston and
Mornington Crescent (did I win?).
http://www.fxfp.com/lib/tube/