Beside a park bench somewhere in London, a man and a woman meet.  It seems they’ve met there many times before.  That’s the foundation of this intriguing, psychological love story – which gives up its secrets in satisfyingly measured doses, and digs into some important questions about human responses to loss.

The story of Lightspeed is told from back to front, beginning with the break-up of a relationship and then rewinding, scene by scene, towards a sweetly awkward courtship.  That device isn’t as innovative as once it was, but it’s used here to commendable effect building up the tension from moment to moment.  When one vignette shows a reconciliation, we know that the next – however lovingly it begins – must end in a quarrel.  And on a larger scale, we quickly learn that both lives have been touched by tragedy; a lot of the play is spent anxiously waiting for the hammer to fall.

It’s those tragedies which underpin the plot of Lightspeed, and drive the personal stories of two subtly damaged characters.  Cleverly, we see the consequences first – the way the two lovers are occasionally driven to push each other away – and it’s only much later that we come to understand just how that fragility arose.  Taran Knight and Francesca Heraghty-Smith both put in understated but emotional performances, developing likeable and utterly credible characters who subtly change as we travel back through time.

The pace, perhaps, is a little too metronomic; while the plot twists themselves are anything but predictable, it’s sometimes too easy to guess when the next one’s coming along.  A couple of character-defining solo scenes do break things up nicely, so I’d have liked to see a little more variety along those lines.  But there’s a clever gimmick involving costume changes and clothes rails, which sees reminders of past revelations literally pile up around the characters; and each short scene is given a gently riddling title, a simple device which lends extra focus to some already-compelling dialogue.

So there’s a great deal to like about Lightspeed – but sadly, there’s also something about its construction which doesn’t quite work for me.  We know that the couple will end up apart, so it’s hard to buy into the optimistic first flush of love (which comes, thanks to the reversed chronology, in the closing minutes of the play).  And it all feels a little too futile – a little too destined to fail.  There’s no particular moment when you wish events had taken a different turn; it just seems that the characters’ psychological burdens are too great an obstacle to overcome.

It’s a shame it ends as a counsel of despair, because there are some vitally important messages just below the surface here – lessons about facing up to grief, learning to trust others, and allowing yourself to heal.  As a simple human story, though, Lightspeed is engaging and well-told, deftly scripted and impeccably delivered by two highly capable actors.  It has some room for development yet, but it’s well worth seeing now.