Orange Tree Theatre Festival, Programme 1, Orange Tree Theatre

Sam Walters, Britain's longest-serving artistic director of a theatre (43 years!), looks to the past as well as the future with his Orange Tree swansong. This varied festival features nine plays and six world premieres across two programmes, all of them staged by returning graduates of the Richmond venue's trainee director scheme.

The diligent Programme One viewer will spot a number of recurring subjects, including science teachers and astrophysicists, the resurfacing in adulthood of childhood dynamics, and constant grappling with faith and mortality.

The thematic throughline lends the evening a pleasing cohesion while providing a distraction from some of a varied bill's weaker moments. An innovatve adaptation of Duck, Death, and the Tulip is the standout - and, indeed, would work as a stand-alone piece - though the programming sustains interest throughout. The Grim Reaper surfaces early in Adam Barnard's Closer Scrutiny, which puts centre-stage a research biologist, Caroline (a largely reactive Eleanor Yates) who proclaims "I'm here to talk to you about death." Her specific reference is in fact the death of cells as evidenced by her experiments on fruit flies. More interested in the physical process of decay than the spiritual or emotional experience, Caroline finds her detachment challenged by the looming demise of her astrophysicist father (Julian Forsyth), a renegade professor who is endearingly awkward in his attempts to bond not just with his estranged daughter but with a mute grandson (doe-eyed Will Devey).

David Lewis's Skeleton brings three adult children home following their father's death and the diagnosis of their mother with Alzheimer's. Despite the grim subject matter, the piece is an old-fashioned romp rife with heightened farce and big punchlines, though the sitcom breeziness of Alex Lass's production does somewhat undercut the emotion. Daughter Claire (fervent Amanda Royle, pictured right), struggles to overcome her adolescent petulance, resenting her parents' preference for charming Joe (wry Ben Warwick); hers is a defined if unnaturally accelerated arc. Joe's coming out is essentially one wacky joke, while eccentric Tom (excellent Paul Gilmore) works on a supermarket fish counter gorging on expired food, all the while spying through a telescope on a neighbour who has a potentially cancerous mole. 

There is perhaps too much material here for a short - the plays range in length from 30 to 45 minutes - given the rushed dissection of faith and home truths that are delivered with a sledgehammer. Nevertheless, the antics do raise a smile, particularly a brandished banana and that old theatrical favourite - the urn of ashes.

German author-illustrator Wolf Erlbruch's 2007 book Duck, Death, and the Tulip introduces children to the fact of mortality through sparse, idiosyncratic illustrations, dark wit, accessible philosophy and a tale of infinite strangeness. And here it arrives winningly translated to the stage by War Horse's Andy Brunskill (he's resident director on the West End company) and Jimmy Grimes and a pair of beautifuly crafted puppets.

As with Joey the horse, Duck (Ashleigh Cheadle) is instantly imbued with personality, waddling with purpose and jerking her long neck as she spies Death (Tom Kirk) on her heels. Her nemesis is a creepy, curiously expressive skeleton in a smock - think E.T. by way of Tim Burton. Eerie images imprint themselves on the mind: Death weightless in the depths of the pond, Duck laying her wing upon him, the two breathing together in connected sleep: all so very odd and so very moving and characteristic of the creativity we have come to expect from this address. Let's hope it continues under the leadership of Walters' successor, Paul Miller. 

• Orange Tree Theatre Festival continues through 29 June