For two hours, the incredibly relaxed figure of Michael Pennington entrances his audience with an affectionate portrait of a man to whom he has devoted 20,000 hours of his life on stage, ignoring innumerable others rehearsing and thinking and writing about Sweet William Shakespeare.
He does so in plain clothes (changed during a 20 minute interval) on a bare stage adorned with nothing more than a period wooden chair, his imagination and prodigious acting skills.
The love affair started early, when the young Pennington was taken to the Old Vic at the age of 11 to see Macbeth. Rather than the anticipated boredom, he was instantly enticed away from his support of Tottenham Hotspur to a completely different kind of devotion, which has still not left him five decades later.
Part of the attraction of this performance is the revelations not only of morsels of information about Shakespeare but also those of his biographer, perhaps most informatively in connection with the English Shakespeare Company that he created together with Michael Bogdanov.
As Shakespeare's story unfolds, it is illustrated by generally short extracts from the plays and occasionally sonnets, with humour often to the fore. Even when Michael Pennington is speaking as himself, the language that he uses often draws on his subject.
Together, they strove to look not only at the rich characters but also the underlying politics and arguments, which frequently have as much relevance today as they did when the plays were written.
Early on, the narrator/biographer identifies the main quality which distinguishes Shakespeare from Kit Marlowe and almost anyone else who has written to the stage. That is his ability to write about characters both high and low in language with which all can identify, whatever their walk of life. In doing so, he engendered a whole new acting style.
He seemingly takes this to heart when scripting his solo acts of worship, giving more attention and prominence to the likes of Mamillius (The Winter's Tale), Dromio of Syracuse (Comedy of Errors), Flute the bellows mender (A Midsummer Night's Dream) and the even lesser-known long-term habitué of death row, Barnadine (Measure for Measure) than the usual suspects.
Indeed, while Macbeth and Hamlet get mentions, their most obvious soliloquies about daggers and existential debate do not get a look in to this human and humane portrait of a man about whom we know so little.
What makes this a special occasion, apart from the use of obscure stories that will not be familiar to many members of the audience, is that rare quality by which, as soon as he drops into Shakespearean mode, the actor completely stills his packed audience. Their fidget-free silence is the best testimony that a performance of this type can have.
Sweet William is only playing for one week, broken up by performances of its companion piece, Anton Chekhov, but fans of either writer should not miss out.
If they do, the likelihood is that they will get another opportunity to witness these bravura events, as they have been touring around for years, filling gaps in this busy actor's agenda. Even so, the comfortable Hampstead Theatre on a cold November night is as good a place as any to catch up with a personable writer/actor so clearly enjoying himself and entertaining his guests.
This production has also been reviewed by Pete Wood at the Tobacco Factory, Bristol, and Rivka Jacobson at Trafalgar Studios.