There is a joke at the start of the fifth episode in this series that due to BBC financial constraints programme budgets are being cut. So Death in Paradise, for example, will now become “a minor injury in Butlins”. And Walliams and Friend will be "Walliams and the Cheapest Available Celebrity”. I don’t know how much this week's guest Miranda Richardson cost but I did wonder how available she was as she doesn’t do a great deal in this episode.

What she does do, however, is a great showcase for her comic talents – not that Blackadder fans ever doubted them. In one sketch she opts for the old cross-dressing prosthetics number to play a blokey estate agent, pricing up des res wardrobes and Mayfair cardboard boxes. In another sketch (pictured) she fronts a new twist on the old injury claims ads, in which people get minor pay-outs for low level office humiliations such as the boss getting their name wrong.

Both of these sketches are impressively strong, as is one where Richardson plays an Ant McPartlin superfan, who is so fixated on him that when she read the recent biography of Ant & Dec she blacked out all the words about Dec. It’s a lovely little character study, a bit Victoria Wood, but with an added level of demented darkness that makes it feel more contemporary.

Elsewhere Walliams also has a great time getting his teeth into a strong script, most notably in a two-hander with Morgana Robinson (why not Richardson?) where the dialogue consists mainly of film titles (obvious but still funny and clever) and in another skit in which he pitches a totally inappropriate Harry Potter sequel. I could probably do without his Middle Class Jeremy Kyle running gag again but the programme was clearly aware that they would be stretching the idea to snapping point by now as they come up with a new twist on its fifth outing. Give the beefy security guy his own series.

Watch on iPlayer here.