As we know, Act III of Tosca takes place in a castle. But in Keith Warner's production in the very real-life St Olaf's Castle in Savonlinna, so does Act I. We hear those three portentous chords from the brass and immediately see a rope dangling from the vertiginous parapet, followed by the swish of a dark cloak as Juha Kotilainen's Angelotti abseils down to make a dash for the Attavanti chapel. It's a real coup de théâtre to get things started.

Given the phenomenally atmospheric surroundings of the castle and the choice of period dress (the Napoleonic military costumes are immaculate), designer Jason Southgate doesn't feel the need to overdo the sets. A set of chapels surrounds a central bathtub-shaped object in the centre of stage which is transformed by turns into altar table, Scarpia's dining table and eventually coffin. The near-impossibility of set changes in Olavinlinna's narrow stage is solved by stagecraft alone: anything which doesn't fit the current act is simply ignored. You might think it wouldn't be effective, but it is, partly because of revival director Anselmi Hirvonen's attention to detail in the acting. Angelotti is continually terrified by the clank of a gate or the thump of something he's tripped over, the gaoler cuts a slight self-satisfied caper as he pockets Cavaradossi's ring, Scarpia gives an ironic slow hand clap to Tosca's “Vissi d'arte”, you see the sudden change in the eyes of Johanna Rusanen's Tosca expression as she spots the knife and realises the possibility of freeing herself and the world from Scarpia.

It was a big night for Rusanen – her role début in front of a home crowd – and it may have been early nerves that added a slight hard edge to her voice at the start. But a few minutes into Act I, her voice seemed to smooth out as she relaxed into the role. By the end of the act, she was both sounding and looking very assured: she certainly isn't short of power for the role even in Savonlinna's substantial (2,300 seat) arena, and she has a good feel for Puccini's phrasing as well as the dramatic ability that the role requires. In Act II, her interplay with Elia Fabbian's Scarpia was electric.

Fabbian is demonically good looking, which added to the sexual terror of his pursuit of Tosca. As well as a fine acting performance, he also turned in a credible vocal effort: his voice was just about big enough to rise above orchestra and chorus in the Te Deum, no mean feat given that the orchestra pulled all the stops out and the chorus nearly blew the roof off with the volume of sound.

Kamen Chanev was at his best in Cavaradossi's big solo numbers: both “Recondita armonia” and “E lucevan le stelle” were well delivered. His opening scene with Angelotti and Juha Eskelinen's characterful Sacristan worked well, but his dialogue with Tosca didn't really achieve the playful sparkle that are produced by the best pairings. His Act III was better, with attractive timbre and good legato in the voice making up for limited acting.

Given how many times I've seen Tosca by now (as, I expect, have many of the audience), it takes something special to make Act II dramatic enough to set my pulse thumping and feel as involved as if I'm seeing it for the first time. But that's exactly what Rusanen and Fabbian delivered, with the help of solid conducting by Philippe Auguin. The orchestral performance may have been short on Puccini string swell (I didn't count, but I suspect the number of violins and violas may have been a bit thin), but it was long on just about everything else: power from the brass, pure timbre and clarity from woodwind and a good sense of balance throughout.

This Tosca has a lot going for it: good setting in amazing surroundings, top class orchestral and choral performances and high quality singing from the three lead roles. But most of all, it made me believe in the story all over again and come out with my nerves jangling. You can't ask for much more.