I admit it, I applauded Harri Nykanen’s Nights of Awe when it first appeared in English in 2012.

Its central protagonist, Ariel Kafka, was an intriguing addition to Scandi-noir fiction, being, as he is in Nykanen’s imagination, one of Finland’s only two Jewish cops. Kafka — which is apparently a bona fide Finnish Jewish name — is gloomy, with an unsuccessful love life but a rather better track record in solving crime.

All four of the Kafka thrillers have appeared in German but are being published in English rather more slowly.

I am sorry to say that, on the evidence of Holy Ceremony (£8.99) — the third in the series — the UK publishers, the adventurous Bitter Lemon Press, need not rush to bring out more.

This book is a mess, giving every sign of having been thrown at the screen, with any reference to Kafka’s Jewish identity flung in with a kind of bolt-on carelessness that would make anyone wonder what it was doing there.

The opening is intriguing: a woman’s body is found covered in scrawled religious texts. “We Jews know our Old Testament”, Kafka confides to the reader. But the texts lead to a ludicrous sub-Dan Brown Grail secret society, whose members met at school and are being killed off, one by one.

Nykanen, a former crime reporter, who is not Jewish, crowds his pages with near-impenetrable Finnish names and geography. I completely lost track, at one point, of who was who, not least because there are at least three sets of brothers in Holy Ceremony, including Ariel Kafka himself and his successful elder brother, Eli the lawyer.

In between the police procedural there is an obligatory — and wildly unconvincing — Jewish section, in which Kafka improbably is recruited to help run the Helsinki Jewish community centre and has a conversation with his brother Eli about Pesach.

“You’re coming to Seder, right?” insists Eli. Nykanen then informs his readers: “Seder was an important part of Pesach”.

If you are going to make your police hero Jewish, at least let that have some impact on solving the crime.

This doesn’t apply here at all. Much more unholy meltdown than holy ceremony, I’m afraid.

JENni FRAZER