You Only Live Forever, Assembly George Square Studios (Venue 17) ****
Olga (Dunn) and Imi (Metcalf) meet in Las Vegas and fall in love, but not before Imi meets an inventor in a casino bar and drinks what he laughingly calls the elixir of life. Back in London, they settle down and have a child. The years pass and Olga ages, but Imi remains remarkably unchanged. Soon, they are going to increasingly complex lengths to conceal the yawning age-gap.
There is lot to explore here: the emotional impact of outliving first your partner, then your children; the eventually wearying effect of eternal youth. The duo doesn’t shirk these things, but always has a gag or two at hand to pull the show back if it’s in danger of tipping over into schmaltz.And they have fun imagining the future: people have finger phones and eat in zero-gravity restaurants, cars are museum pieces and polar bears extinct.
The decision to come out of character and intersperse the play with scenes in which they argue about their writing process is less successful; it helps develop the double-act dynamic, but slows the action down. Putting greater trust in their story might lead to these scenes being reduced.
The fact is, there is plenty to trust. A complex and far-reaching story is adeptly managed, with lifetimes explored through carefully chosen moments, emotional journeys undertaken and satisfying conclusions reached. Add to this the pair’s natural comic abilities and you have a show full of things to like.
• Until 27 August, 1:35pm