Endeavour’s skills are tested to the limit.

ITV’s Endeavour kept nearly 5.5 million of us perched on the edge of our seats again this week. Before we get to Barrington Pheloung’s spine tingling theme tune at the end, this week’s episode served up an impressive body count, more than a liberal sprinkling of Oxford’s dreaming spires and another intricate and compelling storyline. As if to punctuate the point further even the climax is fittingly set among these very spires. The plot is driven by a medley of soprano duets, arias and sonatas which proves a mesmerising cocktail.

In Fugue, when a woman is found strangled in a railway waggon at first it is assumed the man she’s having an affair with has killed her. A monogramed scarf left on the victim leads Morse to think otherwise, especially when he discovers the words from the last line of the opera, Othello written at the crime scene. Other victims subsequently surface and with similar cryptic messages left at the scene. The serial killer who has a penchant for playing complex psychological games, shares not only Endeavour’s intellect but his passion for opera. The murders, inspired by the plot of operas lead to Chief Superintendent Bright finally relieving Morse of general duties, asking him to ‘prove himself useful’ thanks to his specialist knowledge – Yes, the plot is tailor-made for Endeavour.

Roger Allam as Morse’s immediate superior, DI Thursday is a real scene stealer. Why does the phrase ‘cool cat’ come to mind with him? Maybe it’s those hats, the pipe or that honeyed voice of his. In any event, there’s a great deal of mutual respect and appreciation between the two main characters. At the point when we meet Thursday’s family for the first time, there is a sense of Endeavour’s desperate need for familial affection, perhaps to serve as a buffer between the demands of the day job and his sanity. By the time we get to the emotionally charged conclusion Endeavour loses his grip, becomes emotional, weary and deeply tormented by his intellect. It is comforting, even though inappropriate to see Thursday take on a father-like nurturing role.

Abigail Thaw returns as Dorothea Frazil, editor of the Oxford Mail and delivers up a no-nonsense, savvy, smart yet ever so slightly crafty newswoman. Kinda reminds me of someone but for a few touches here and there. No hints necessary.

All said, as complex as is this week’s plot, I found it less difficult to guess the killer this week than last week. Nevertheless it makes for must-see TV and a perfect way to wrap up any weekend. Shame there’s only two more episodes to come. So hoping for another series… or I’ll have to resort to being a tourist amongst the rooftops of Oxford, complete with opera on my iPod, if only to preserve the magic.