If (and it’s a big if) you can accept the central conceit of Your Obedient Servant (Hudson aping his betters) then there’s a great deal to enjoy in this episode. And even if you can’t, Fay Weldon’s script still sparkles.

The opening scene intercuts between Hudson (in his parlour) and Richard Bellamy (in the morning room) both of whom are more than a little irritated by the constant loud banging and showers of dust appearing all around the house. This is due to a new electric bell system which is being installed by a group of workmen (led by Larry Martyn).

Martyn (probably best known for playing the slightly more aged Mr Mash in Are You Being Served?) is an early recipient of some of Weldon’s top notch dialogue.

That the episode begins with Hudson and Richard Bellamy seems apt, as both are required to deal with the same issue – the surprise arrival of their brother – although their storylines conclude in very different ways.

Even before we learn that Hudson has a brother, Weldon provides him with a lovely little monologue (delivered, as always, exquisitely by Gordon Jackson) in which he lectures a slightly baffled Edward. “A brother, in any walk of life, is someone to whom much is owed. The greatest consideration, the greatest formality, no matter how the exigences of fate have led each into different paths, into different fortunes”.

Hudson certainly abides by these words, although it’s more than a little surprising when he leaves 165 Eaton Place without permission and nips out to hire himself a fine suit of clothes (plus a cane and gloves). It’s all part of his plan to ensure that his brother, Donald (Andrew Downie), his sister-in-law Maudie (Marcia Ashton) and his niece Alice (Kim Hardy) believe him to be a gentleman about town rather than a common servant.

The problem is that nothing we’ve seen of Hudson to date has prepared us for this. Extreme pride in his position has always been his defining feature – possibly it would be easier to understand had Donald had been an aggressive or foreboding man, but on the contrary he’s cheerful and welcoming. True, Maudie is a bit of snob (commenting that waiters aren’t people) but it’s hard to imagine Hudson going through all this rigmarole for her benefit.

If Donald is a thoroughly nice chap, then the same really can’t really be said of Richard’s elder brother, Arthur (John Nettleton). Nettleton (in reality some years younger than David Langdon) gets most of the best lines in the episode and delivers them with relish (his description of Hudson – “a furtive looking fellow with whisky on his breath” – is just one of many).

The regulars aren’t forgotten either. Mrs Bridges has several standout moments, the first being when she recalls an early crisis after the cook fell dead over dinner and she had to step into the breach. “I was only the kitchen maid. They wasn’t grateful. They sent the hollandaise back Said it was curdled. Well the look on that poor dead woman’s face. Enough to curdle anything it was”.

Later she passes over her life savings – thirty pounds – to Hudson. That she’s content to do this (asking no questions) is remarkable. She has total faith that Hudson will be able to repay her one day and hopefully he did so. If he ended up squandering all his savings (not to mention hers) just to entertain his brother for a few days then it would leave a bad taste in the mouth.

Roberts was probably the regular who always had the least to do (although Patsy Smart could work wonders with just a look or a disapproving purse of her lips). Today she’s given a nice monologue in which Roberts recalls how an early love of hers was chased away by her disapproving parents. It’s just a short speech, but it lays bare her lonely and unfulfilled life since.

Despite Arthur’s general waspishness, there are occasional signs that a rapprochement with Richard might be on the cards. But it’s quite telling that Richard eventually spurns him after he attempts to embarrass Hudson. And although Hudson fears for his position when Richard encounters him and his brother eating in the same swanky restaurant as he is, the viewer – no doubt knowing that the series wouldn’t be foolish enough to let Gordon Jackson go – will be one step ahead of Hudson and secure in the knowledge that the master/servant balance will shortly be restored.

A slightly strange episode then, but one that zings with such excellent dialogue that I’m prepared to cut it a great deal of slack. Other things to report – Edward attempts to smoke a pipe which doesn’t go down well with Hudson (“tobacco slows the nervous reflexes and yours are quite slow enough! Put that abominable instrument away and lay out two trays”) and a new parlour maid, Violet (Angela Savy), appears out of nowhere and is never seen again after this episode.