Compulsive neat freak meets chaotic slob: Can their living space survive the conflict?

Martin Harrison keeps himself to himself and his Central London flat as neat as a new pin. Maybe he should loosen up and enjoy more of a social life, but in his mind, that's tantamount to opening the floodgates to emotional chaos. He agrees, however, to join the flat-sitting scheme in his building and look after another tenant's flat in exchange for a similar watch over his when he's travelling for his work.
A floor away in the same building, Russ McNeely is happy with his life as a freelance cook and a self-confessed domestic slob. He also joins the flat-sitting scheme, both to be neighbourly and to help keep his flat in order, as Russ also travels for his work.
For a while, the very dissimilar men never meet. Martin is horrified at the mess at Russ's flat, while Russ finds Martin's minimalist style creepy. But in a spirit of generosity, each of them starts to help the other out by rearranging things in their own inimitable way.
Until the day a hiccup in the schedule brings them face-to-face at last.