I always enjoy Wired Theatre's unconventional site-specific work – partly because they're so willing to break theatrical rules, and partly because they invariably surprise me with something different and new. Set in a real house in Hove, with scenes in the lounge, hallway, kitchen and conservatory, this one certainly preserves Wired's reputation for performing in unusual spaces. But after years presenting shows which hop back and forth in history, this time they gave me the one thing I least expected: a traditional linear storyline.

And that's a smart choice. Always, With A Love That's True is a sequel to last year's show, And Love Walked In, which told the story of a psychologist called Andrew who slowly lost his grip on reality. I'd worried about whether I'd follow the plot without having seen the original, but the story comes out straightforwardly in the first few minutes – and though I suspect I may have missed a nuance or two, there certainly wasn't anything I didn't understand.

The story starts with Andrew plotting revenge against his neighbour, Piotr, whom he blames for stealing his wife Sheila. Piotr then dies of a heart attack; it's ambiguous whether Andrew actually had anything to do with this, though it seems unlikely to me. Either way, the fact that his wishes have come true begins to mess with his mind – and his own past indiscretions are returning to haunt him too, in the form of a client called Jo and her feisty partner, Phyl.

Robin Humphreys leads the cast as Andrew, and delivers a fine performance from beginning to end. Andrew is by no means a likeable character, but Humphreys infuses him with an appealing vulnerability, expressed in the way he crumples into a sofa or leans anxiously against a window to peer in. Director Sylvia Vickers isn't afraid to take her time over character-defining scenes: I grew fidgety watching Andrew slowly make a cup of tea, but then, when he sat down to drink it, I realised I'd witnessed the perfect depiction of a broken lonely man.

Angela Ferns is perfectly-cast as Jo, alternating between quiet outrage at what Andrew's done to her and absent neediness as she falls back within his thrall. Jackie Thomas makes Phyl an image of controlled vengeance, while Gillian Eddison is sensitive as Sheila, reflecting both the loss of her new love and a measure of past affection for her husband. There is often humour in these performances, but there is a lot of quiet emotion too.

One event towards the end felt a little implausible – we have to believe that characters who till then have been gutsy are suddenly easily cowed. And the sequence of scenes in this promenade performance made me tromp back and forth between the hallway and conservatory a little more often than I wanted to. But the organisation and stewarding on the whole are excellent; Wired Theatre have a lot of experience running shows in unusual spaces, and that expertise shows.

Always, With A Love That's True isn't as mind-bending or wacky as some of Wired's previous shows, but it proves that they can deliver results with a conventional narrative, too. Whether or not you saw last year's instalment, you'll enjoy this well-delivered and engaging tale. Book early if you want to see it though – they always sell out.