In the eyes of Gregory Motton's characters, The World's Biggest Diamond is honour. Together with love, this is the subject of an uncomfortable, claustrophobic play.
If nothing else, The World's Biggest Diamond is a rarity at the Royal Court, since it features only two characters, both of whom are beyond retirement age.
The names that they are given in the script for these two oldies - none are mentioned on stage - are the bland and almost pseudonymous Mr Smith and Mrs Thomas.
Michael Feast plays a disabled man in his early seventies who is suffering from a terminal disease. He receives a visit from his former lover played by Jane Asher, looking uncannily like Catherine Deneuve.
For the next 100 minutes, the couple discuss the profound nature of their love for each other and an affair that had ended over thirty years before. The action, or more accurately for the most part, inaction, takes place either in the man's cottage or on the seafront of the cut-off island where he lives, nicely conveyed by Emma Laxton's sound design packed with seagulls and pounding waves.
The pair combine recriminations with fond recollections and it is soon clear in Simon Usher's production that despite the separation that has lasted for almost half of the length of their lives, there is a deep, compassionate love that still lingers.
The problem that slowly emerges was that the man was married and unwilling to commit to the beautiful teenaged law student. So many years later she has become the glamorous 60 year-old who has now come to pay her final respects, unseen husband Gareth in tow.
The couple agonise at remarkable length about past wrongdoings and the lost love that both in retrospect believe should never have disappeared.
At its best, The World's Biggest Diamond contains moments of comedy, tenderness and sometimes explosive frustration as a man and woman explore their past, both together and apart.
The acting is wonderful with both Feast and Miss Asher giving very moving performances. Eventually though, the writing becomes repetitive, as we see every minor variation on what is anyway a very narrow theme.