Key points:

• Leeches, breech births and heroin … it’s the typical blend of health-related crises and social analysis in another merry exceptional that yanks on the heartstrings.

The uplifting news about the bloodsucker, says Dr Turner, “is it’s a sizeable example, so you won’t require more than the one.” Thank goodness. I thought he was going to put the entire container of parasites – clinical grade, gathered from Barts that morning – on to poor Lucille’s swollen and enlarged eye, and that the Call the Midwife Christmas exceptional (BBC One) was going to take a shocking turn. I can manage a touch of blood – you need to with this show – yet there’s a distinction between birthing matters (“I have quite recently lost the greatest bodily fluid fitting you’ve at any point seen!” reports Mrs Howells, prospective mother-of-five) and squirming parasites, going to be joined inside the area of an eyeball.

The bruised eye is a hen night injury – a hazardous blend of the Nonnatus House steps and Sister Hilda’s rum punch. Sister Hilda is recuperating with headache medicine; for Lucille, it’s parasites, treatment “from the third century BC!” says Sister Monica Joan, with happiness. “I feel debilitated simply seeing them,” says student Nancy, while Lucille shudders with loathsomeness. Later scarcely 60 minutes, the parasite is full; by this point on Christmas Day, we may all know how it feels.

Lucille has returned to her lovely self, and her Boxing Day wedding to Cyril is saved. Yet, there is inconvenience gestating somewhere else, and I don’t simply mean the split in Fred Buckle’s Santa pants. The birthing specialists of Nonnatus House are anticipating a flood of ladies – an additional 20 patients relegated from St Cuthbert’s emergency clinic. “What do you assume was happening in March?” asks Nancy, with a grin. There are insufficient birthing specialists, then, at that point, and presently.