eware of the agapanthus,” read a sign at Faringdon, the famously idyllic Oxfordshire home of the composer, novelist and aesthete Lord Berners. But it wasn’t the garden of which visitors – the glittering roll call included Gertrude Stein, Nancy Mitford, Igor Stravinsky and Salvador Dalí – needed to take care. In its heyday, Faringdon was a noted weekend haven, a stage set on which guests were invited thoroughly to enjoy themselves so long as they remembered always to play a suitably witty role. However, beyond the jokes and the ice-cold martinis could be discerned a fierce tinge of pain, the prime cause of which seemed mostly to be Berners’s younger lover, Robert Heber-Percy, aka the Mad Boy. It was this creature, dashing but often cruel, whom one had to approach with caution.