REVIEW: Blood Brothers, Mayflower, Southampton, until Saturday, September 22.

Willy Russell’s modern masterpiece simply gets better and better – thanks here to Niki Evans who absolutely nails the role of Mrs Johnstone, the tragic, impoverished, Liverpudlian mum driven by desperation to seal a pact with the devil.

Pregnant yet again, she consents to her new twins being separated at birth, the one fated to stay with her in the rough end of town, the other given away to grow up in the lap of (relative) luxury – a secret deal with devastating consequences for all concerned.

The brilliance of the musical is that we begin with the ending – and then sit back for the story to unfurl until we end with the beginning. But however much you know it’s coming, the impact is huge as the cheeky, jokey first half gives way to the darkness of the second.

Nature runs into nurture and class does battle with superstition in a tale which packs the most powerful of punches. Yes, it’s a show which quite deliberately sets out to tug at your heart strings– but it would take the hardest of hearts to resist it.

At the core of the show is a terrific performance from Sean Jones as Mickey, the twin who stays behind. Jones goes from exuberant, upbeat, irrepressible kid to shattered, drugged-up, broken man in a remarkable, compelling and utterly convincing transformation.

Olivia Sloyan as his girlfriend/wife Linda beautifully conveys the human cost as all those youthful hopes and dreams are crushed.

Holding it all together, Marti Pellow cuts an imposing figure as the narrator – though just occasionally you find yourself wishing for a greater clarity with the delivery. After all, it’s the narrator who gets some of best lines in a show jam-packed with wit and genuine pathos. Just at the moment, Pellow is not quite wringing out every last drop – a minor quibble amid the wider painful pleasures of seeing Mrs J and her offspring hurtle towards their doom.

Phil Hewitt.