The article is short enough that it needs no summary here. This bit, however, I found hilarious and grim -- as any playwright would:
Catastrophe is a short work consisting of one scene, in which a director and his assistant discuss a mute figure they are preparing for a performance: he is a dehumanised character, like a tailor's dummy, at the mercy of their direction; his only gesture of independence is to raise his head at the end of the play – an act of resistance in the face of oppression.
Knowlson recalls Beckett's furious response when a critic described the ending as ambiguous. "I can still remember sitting with him outside a cafe in Paris," he says. The playwright pounded the table and told him: "It's not ambiguous – he's saying, 'You bastards, you haven't finished me yet!'"