An inspector calls: intrepid eyebright Paul Celan stalks Herr Doktor Heidegger to his Hütte on the mountain named for death, where gnomically they rehash their lives. Celan presses the question, Heidegger evades him, falling back into steamy memories of Hannah Arendt and her green dress. All the actors are English and have English accents save Heidegger, played by the great Joss Ackland, man of White Mischief, who rolls his South African growl into the jocular menace of a German master. The play captures little or nothing of the poet’s anguish or his poetry, but consider the possibilities: Paul Celan, P.I.