A bare hospital bed, the grim glow of a cardiac monitor; violins swelling to a crescendo – the opening of Peter Skidmore’s latest production An Earlier Heaven seems to anticipate the vivid and masterful visuals of last year’s spectacular When the Rain Stops Falling, which had the same production team.

Unfortunately, despite its moments of gleeful absurdist humour, the script often fails to live up to its promising start – and as a result, so do the actors. There are clever moments: a painting of flowers is carefully propped up against a real bouquet of identical flowers, to give a coma-victim “something pretty to look at”; the garish makeup on the dying woman’s face is first funny, then horrific and finally poignant. But the transition from funny to painful does not happen so smoothly elsewhere: jokes often fall flat, and serious episodes seem mawkish.

Perhaps this comes from the difficulty of doing an original hospital-based black comedy: with the popularity TV programmes like Scrubs and Green Wing comes the expectation of ‘weirdness’ in hospital comedy. The most bizarre moments in An Earlier Heaven were, therefore, also the most funny. At one point, for instance,  Gavin (Harry Gower) heaves himself onto his comatose mother’s convulsing body, bringing both himself and the 80-year-old crashing to the floor; the shocked silence that follows is broken by his brother Henry (Sam Sloman): “Well done, Norman Bates, you’ve literally just killed your own mother with your body.” However, subsequent jokes about smuggling the mother out in a blanket and “shitting on the patient” don’t feel shocking enough to work.

Relationships between the characters are sometimes frustratingly underdeveloped. Sibling rivalry is expressed in the most clichéd of terms – “you always got the big bedroom when we went to Norfolk”, peppered with quips about “the state of the NHS these days” and limp jokes such as: “Thorntons Continentals – I suppose Mum always was a keen proponent of the EU”. Even if the jokes were deliberately bad, the effect on the audience is bemusement rather than comedy. Gower as the younger brother was particularly shaky in his delivery, although perhaps this was a case of first-night nerves.

But when the comedy does work, it works well: Bea Svistunenko and Helena Blair as two “beady old ladies” are a hilarious delight. The play was saved by its final scene, with a strong performance from Tom Stuchfield as an almost-grieving husband. At this point, the play achieves what it has been straining at all along: a poignant melding of the playful and painful.