100:00:02,320 --> 00:00:04,312(THEME MUSIC PLAYING)200:00:35,680 --> 00:00:37,399DAVID ATTENBOROUGH:<i>In the far north,</i>300:00:38,520 --> 00:00:41,319<i>after three dark months of winter,</i>400:00:47,080 --> 00:00:49,515<i>a world is waiting</i>500:00:53,000 --> 00:00:54,639<i>for a trigger.</i>6