The Luck of the Vails, by E.F.Benson
An Edwardian thriller, with clear influence from Oscar Wilde, especially The Picture of Dorian Gray (US link), this is a gripping crime novel that makes it clear what will happen early on and provides all the tension in whether the murder attempt will come off and who will be involved.
It splits the difference between a thriller and a detective novel, and has some of the classic elements of country house mysteries, including a secret passage. There are some excellent moments of tension. I gasped at times.
Throughout the book you have the combined sense of not knowing if they will catch the crook and the rising anxiety that he will succeed. It is, in that sense, a combination of Agatha Christie and Columbo. Benson's other crime novel, The Blotting Book (US link) has a similar combination of detection and thriller.
One of the original reviews said this:
the most interesting portion of the book is melodrama. There is an ordinary pleasant love story, and there is some light, bantering dialogue, enough to give it the flavour of a society novel. But we pay little heed to these. The setting might just as well have been mediaeval, for it is the jewelled Luck, and the perils by fire and rain and frost of the young hero, and the creeping wiles of the crafty villain, and his dark exits and entrances by secret staircases, that hold us fast.
That's a great summary. I do love the melodrama, especially in the gentlemanly, understated way that Benson provides it. The horror of what might happen is subtle which only makes the tension better.