The episode opens with a cross-fade from the empty hallway (albeit with a new object – a perambulator – prominent) to the kitchen and parlour, where the servants are all in silent contemplation. Given Upstairs Downstairs‘ large cast, it’s rare for an episode to feature every regular – and so it proves today as Rose and Ruby are absent.

It’s a mystery where Ruby is (not to mention who’s doing her work in her absence) but at least Rose gets a namecheck. Given that Out of the Everywhere sees the return of Miss Elizabeth (complete with her baby daughter) it’s a little surprising not to see Rose, but in her absence, Sarah steps forward to fill the void as Elizabeth’s moral conscience.

There’s a rare moment of contentment downstairs after Hudson, welcoming Richard and Lady Marjorie back home, passes on the news that Elizabeth has given birth to a baby girl. Although Mrs Bridges can’t resist a spot of gentle chiding – Hudson (as befits a man) failed to ask any further questions, such as the baby’s name or weight ….

Even the sour-faced Roberts joins in the jollification as Hudson agrees (after a moment’s pause) that they can wet the baby’s head with a tot of beer. Although it doesn’t take too long for the peace to be shattered once it’s revealed that Nanny Webster (Daphne Heard) is returning to take charge of the child.

Hudson reacts to the news with barely surpassed dismay, telling Lady Marjorie that he’d thought she might have retired (“you mean you hoped she had” mutters Richard out of the corner of his mouth). Nanny Webster appears, in episode terms, about five minutes later – which is still long enough for a sense of foreboding to begin to build.

It’s interesting that we don’t see the response of the other staff to the news of her arrival, instead there’s a sharp cut to the front door, where – a vision in black – the imposing Nanny Webster, scowling at Hudson, impatiently demands to be let in. That she comes in through the front door, rather than the servant’s entrance, and the fact she’s remarkably outspoken to Lady Marjorie (despairing that she’s not wearing her corset) marks her out as a servant with very special privileges.

This really is Heard’s episode, and she dominates it from her first to her last scene, deftly creating the complex character of Nanny Webster in around forty minutes of screentime. Although Nanny Webster is autocratic and capable of finding fault with everything that Sarah does, there’s no denying the love she has for her little charge. There’s also no suggestion that she’s deliberately cruel or careless, it’s simply that her failing energy means that a disaster seems ever more likely as time goes on.

With Richard and Lady Marjorie urgently called away to Southwold (as always, an excellent plot device whenever characters need to be moved offstage for a while) it falls to Sarah to break the news about Nanny’s incapacity to Elizabeth. This isn’t easy though, as Elizabeth initially doesn’t seem at all bothered.

Elizabeth has tended to be painted as rather selfish and self-absorbed since her debut appearance, and today’s episode carries on this trend. That she seems more concerned about going out to a party or finishing her book than learning about her child hardly paints her in the best light.  It’s quite notable that she only visits the nursery quite late on in the episode, although that might be down to her own awkward relationship with Nanny Webster rather than disinterest in her daughter.

And to give her some credit, eventually she does begin to take more of an interest and although she can make no headway with Nanny herself, she ensures that Lady Marjorie gives her her marching orders. This is an exquisitely played scene between Rachel Gurney and Daphne Heard, in which all of Nanny’s arrogance is stripped away to reveal the real woman underneath (one who accepts that she can’t carry on, but still has her pride – sticking to the fiction that she’s only leaving because the stairs are too much for her).

Also of interest is the final appearance by Ian Ogilvy as Lawrence Kirbridge. It’s very low-key (he slips away from the christening never to return) but it works – in this case, less is more.

A strong episode then, although not one with any shocks or surprises (it seemed pretty obvious from the start that Nanny Webster would turn out to be unsuitable). A pity that both Christopher Beeny and Pauline Collins separately indulge in spots of overacting, but you can’t have everything.