Caroline Framke Chief TV CriticWhen the night first starts to go south, Arabella (Michaela Coel) chalks it up to a mistake she’s made before. After promising herself that she’d stay sober, get productive and be good, she gives in to her restlessness and goes out for “just one drink.” Some time later — impossible to tell how much — she wakes up right back where she started, as if shaken out of a nightmare.