Mad
These days I wonder whether she’s gone East Ham
East Ham is one stop short of Barking on the London Underground
M & N – 1980s
Mark & Naomi
On the District & HammerCity lines, for those who care about that sort of thing. (Of course it’s one stop BEYOND Barking if you’re travelling in the other direction.)
The origin of “barking mad” is obscure, but it possibly originated in USA during 19ᵗʰ century, derived from the barking of a rabid dog