UpDown was rarely the sort of series to indulge itself with showy directorial flourishes, but the opening shot of this episode – we see a worried Lady Marjorie through a rain-soaked window – is quite nice.

She’s concerned about a bill that’s been forwarded onto her from a jewellers – James has run up quite a debt with them. Lady Marjorie – always keen to think the best of her son – worries that he’s fallen into bad company, gambling with his brother officers (who can easily afford to shrug off substantial losses as matters of no consequence).

But Richard points out that these aren’t gambling debts – jewels suggest a young woman. Richard goes on to surmise that he’s fallen into the clutches of an unprincipled female who intends to take him for every penny that he’s got.

Just to hammer this point home, the action then cuts to Sarah (wearing a hat that certainly catches the eye). She fits the bill of a gold-digger, but it’s interesting how the episode is quick to turn this idea on its head. James has got large gambling debts and he obtained the jewels in order to pawn them (thereby raising a little money). Sarah is doing her best to help him, but it’s plain that he’s in a desperate situation.

James’ commanding officer, Colonel Winter (Moray Watson), pays a visit to 165 Eaton Place. Watson could play this sort of role in his sleep, but he’s still very watchable – Winter makes polite smalltalk with Lady Marjorie and Richard for a few minutes before breaking the bad news. James is drinking far too much and running up debts at a rate of knots.

That would be enough to generate a decent episode’s worth of drama by itself, but everything then moves up several notches after Sarah tells James that she’s pregnant (“there’s a little captain on the way” as she puts it). Thankfully, this bombshell means that Sarah stops acting in a manic manner (when Pauline Collins is in full flight it’s a little difficult to take).

Rose has arrived to take tea in the servants hall and has a letter waiting for her from Sarah. Mr Hudson and Mrs Bridges are incensed that she has the nerve to write (following the scene she made at Miss Elizabeth’s wedding) but the younger servants, like Edward, are much more indulgent.

Rose later visits Sarah and she shares her news. After a moment of shock, Rose decides that James has to do the right thing by her. Despite Rose’s obvious affection for Mr James, all of her sympathy lies with Sarah (who begins to wail in a rather over the top manner).

James meets with his parents and comes clean. As you might expect, Lady Marjorie doesn’t react kindly to the news that James has fathered a child with their former parlour maid. She’s too far well bred to make a scene though – instead her features simply set into immobility.

Mrs Bridges isn’t surprised to learn about James’ gambling debts. She mutters darkly about James’ Uncle Bertie, which helps to fill in another chink of the Southwold family tree (they seem to be mainly comprised of dissolute spendthrifts, at least according to her occasional reminiscences).

The arrival of Sarah sets the servants’ tongues a wagging – especially when she’s invited upstairs. If there’s a problem to be fixed, then Sir Geoffrey Dillon (Raymond Huntley) is your man. He’s got it all worked out – Sarah moves down to Southwold and eventually – after the child is born – will be found a suitable job, in the laundry maybe.  Sarah doesn’t react very well to this ….

James comes over as rather spineless in this scene. Whilst Sir Geoffrey intones, James says very little – unable to meet Sarah’s eye or respond to her pleas. Eventually he does speak a few words to her (“I’ll write to you”). This comment is greeted with a faint smile and a nod of the head. For all that Pauline Collins can go over the top at the drop of a hat, this is a subtle moment.

James is banished to India – which writes out Simon Williams until the final episode of series two.  That’s a shame, but by the time he finally returns he does become more of a central character.

The final line of the episode (Sarah’s “Rose, I’m frightened”) manages to strip away all of Sarah’s brittle bravado to reveal a more vulnerable woman underneath. Mind you, I’ve a feeling that she’ll bounce back ….