Hello, Norma Jeane (King's Head Theatre)

Marilyn Monroe: Hollywood icon, femme fatale, secret Essex granny.

You read it right. What if her tragic death was a sham and she spent her days in a Brit backwater – but forty years on wants to stage a comeback, giving Hollywood the shock of its life?

That's the fantasy premise which sustains new play Hello Norma Jeane for two hours' running time (including interval), just.

Allo Allo's Vicki Michelle is a dab hand Es-sexing it up as Lynnie, 76, in a crummy LA motel room, persuading her gay grandson Jo to believe her "true" identity. He has to work out if she's quackers or not – and his imaginary friend, Marilyn, poutingly played by Farrel Hegarty – isn't helping one bit.

Her presence is a cute trick which keeps the script more than a string of one-liners for the excellent Michelle to deliver with saucy laugh or gleeful shake of the head.

Jamie Hutchins is good as exasperated, confused grandson Jo, the earnest, caring Essex lad who needs to shake his cheating boyfriend if he could only muster the Marilyn nerve.

Some fun twists – such as "CIA agent" and well-sculpted Arron Blake, a sexy, surprisingly sweet love interest for Jo – and dynamic direction from Matthew Gould keep the pace from dragging.

A third of the script could have been culled as the first nearly half loses its way and there's one too many predictable scenes – thankfully Michelle's verve keeps the Monroe swagger firmly centre stage.