You're right about Davies. I watched the first bit of tonight's episode before my Christopher Lee programme started at 7:15, and was reminded that Davies (and / or the rest of the creative team) not only writes vivid and witty dialogue, but even inserts clever little bits of symbolism and makes his settings really work to support and enrich the script. Oh, and I thought it was a nice touch that they'd persuaded Andrew Marr to present the disaster coverage from Downing Street, too!