Not the worst episode of the season - I managed to get through it, unlike The Axeman Cometh - but oh, it was weak. There was a huge plot hole right at the end regarding when Lord Holm's memory lapses are supposed to have begun; he wasn't on the drug causing them at the time. Doesn't help that he was a repellent character, a typical case of a man sliming after a woman at least twenty years his junior being presented as sympathetic or humorous - ugh, ugh, ugh. The background of the initial crime was wildly improbable and repellent. The idea of a camera obscura being placed in a village and anyone being able to use it to watch people was a bit eyebrow-raising; less like security cameras than open slather for spying. Even the joke at the end was weird - I hope Barnaby wasn't suggesting turning up on Cully and Simon's honeymoon!