Polyglot, a group set up by director Leona Heimfeld "dedicated to exploring issues raised by the Holocaust", clearly relishes a challenge. And its latest endeavour, In Extremis (Young Vic Studio), meets it with surprising success. Striking a cautious balance between collective storytelling and individual testimonies, the piece avoids buckling under the weight of the topic by sticking to a theme of "survival". It is this that links four plays (by Bonnie Greer, Bernard Kops, Peter Wolf and Maggie O'Kane) and a quartet of "moments", in which we see the flickering flame of a life suddenly steady. The opening sequence, based on Heimford's mother's account of being scrutinised by Josef Mengele after arriving at Auschwitz, establishes a tone of simple inventiveness. The doctor, weighing up her age and fitness to work, instructs her to keep turning round. His act of inhumanity is transformed by a theatrical gesture: the actress's slow- spinning dance wordlessly affirms the girl's untouchable innocence.
The best material in In Extremis avoids crude expository dialogue for this kind of subtle articulation, connecting the survival instinct to the imaginative impulse that fringe theatre thrives on: making a feast out of bare bones. One of the most touching moments is "Susan's Tale", in which we see three women squatting on a wooden table-top, each sharing precise memories of breakfast for the others to drool over. Sometimes the gentleness threatens to mire the project's momentum, but only the too-convenient dramatic pay-off of Bonny Greer's otherwise affecting "You", in which a surrogate Auschwitz "family" reunites in Israel after the war, tastes of a post-rationing sugar-binge.
At the opposite end of the same extreme, Volcano TC's The Message (Lyric, Hammersmith) uses similar descriptions of the horrors of the Final Solution, but whereas with Polyglot these are shared between audience and actor, here Nigel Charnock's company is uber-alles. What the message is exactly is unclear, but given that the basic outline of the piece is provided by Tony Harrison's Oresteia, we can assume that it is, probably, the medium. The four-strong cast slam into each other, spewing the poet's headache- inducing word-brew ("Shagammemnon, shameless and shaft-happy etc") as though gargling in their own blood-libations. The sheer excess of the exercise is worth a look-in: texts from Macbeth, Paul Celan, Primo Levi and journalist Fergal Keane plus personal anecdotes, all spliced into nouveau-Aeschylus against a techno-soundtrack and Andrew Jones's brash visuals. This is the closest the Furies get to playing Wembley.
Where it falls down, inevitably, is in the taste department. Maggie O'Kane's Bosnian reportage was juxtaposed discreetly with a German retreat in "Miracle in a Potato Field, her contribution to In Extremis, but in The Message we swing violently from, say, a description of a Jewish orchestra drowning out the cries of their burning brethren to a lip-synching, balloon-popping cabaret turn. Are we to cry or laugh? Or shrug? We're clearly meant to laugh at this exchange between Curtis and Cricket in Viper's Opium (Drill Hall): "The world is fucked"/ "People are good, basically"/ "Oh, how very Anne Frank of you." It's typical high-camp from Mark Pinkosh's superbly neurotic gay adrift in LA. He briefly meets his match in the pathologically optimistic Cricket (Kathryn Howden), but this show by Starving Artists, running in tandem with its Edinburgh Fringe stablemate Road Movie, works better when the pair are doing bleak solo spots: he, putting a brave face on things; she, crumpling with "the grief we have stuck in our hearts... in our intestines".
'In Extremis', Young Vic, London SE1 (0171-928 6363) to 22 Mar; 'The Message', Lyric Hammersmith, London W6 (0181 741 2311) to 15 Mar; 'Viper's Opium', Drill Hall, London WC1 (0171 637 8270) to 27 MarReuse content