This week, they learn about dogging.
Welcome to the World of Gatiss. Just as an episode from Moffat means feisty women and spoddy whizzkids, so from a Mark Gatiss episode of Sherlock, we can reasonably expect dead daddies, suspicious offal, and Kensington gore. In this case, served up with devilish humour and abundant references to Withnail and I. Onwards: for science, UST, and daddy issues!