Lyric, BelfastAnna Healy and Patrick O'Kane give nuanced performances as a volatile, long-married couple bunkered in a cottage that's being slowly engulfed by fire It is difficult to concentrate on writing a memoir when a nuclear reactor is flashing nearby and neighbours are killing themselves. Playwright John Morton and director Jimmy Fay wring maximum dark humour from this dystopian two-hander, set in 2048 at the e…