RARELY has a podcast advert been better placed. In the midst of the vampiric blood lust, starvation, and self-harm that characterised Tom Holland’s account of St Catherine of Siena — as told on The Rest is History (released on Thursday of last week on all podcast platforms) — there appeared a plug for a therapy service. Oh, how the course of 14th-century papal history might have been altered had the young Catherine been able to offload her woes — the death of her twin sister, her controlling parents, and her social-status anxiety — to a compassionate shrink! As Holland’s co-presenter, Dominic Sandbrook, declared, “To the 21st-century reader, it is obvious what is going on.”

Sandbrook’s part in the programme was to utter the occasional Protestant jeer and “Crikey!” when things got fruity. It was Holland, a narrator more attuned to the extravagances of medieval religious sensibilities, who took responsibility for the historical account, and for defending Catherine against a glib post-Freudian diagnosis. There was, he argued, a way of reconciling medieval and modern psychologies; and he went on to make the case for Catherine as an alienated lower-middle-class feminist.

Sadly, the Hammer Horror material pushed to the margins of this programme a full account of what made Catherine such a “significant geo-political player” — something about the Avignon papacy and the Great Schism. But that sort of content doesn’t sell advertising space for therapists.

The novelist Sophie Hannah is familiar with the challenge of balancing character and plot. Best known for her psychological whodunnits, since 2014, Hannah has been charged with the task of continuing the legend of Hercule Poirot. A new one is out soon, and the World Service issued an episode of In the Studio (Tuesday of last week), in which we encounter how the author engages with the project over a four-year period.

In late 2018, she is preparing the third book for an imminent deadline, and taking crucial decisions about commas. The following spring, there is pushback over her ending, which — to the panel of readers, and somebody from the Christie estate — is too open-ended. Hannah is nothing if not agreeable (at least on the record), and a solution is found; but the episode leaves us with a vivid picture of the workings of the book trade, and the part played by authorship within it.

We are all now trained to spot the unreliable narrator; so we should by now have forgiven Bruce Chatwin his lapses from journalistic veracity in books such as Songlines and In Patagonia. The latter has been dramatised for Radio 4 (Drama on 4, Sunday) by Sebastian Baczkiewicz, and much of the whimsicality of the original makes it into this entertaining adaptation. But Chatwin’s perceived deception about his sexuality and the nature of his illness (which post-dated the Patagonia adventure by some years) is not allowed to go unremarked; and, in this version, he is crudely outed on both. Perhaps this is the price that Chatwin must pay for his reinstatement as one of the greatest travel writers of all time.