Ooh it's a long story Sonkie, but basically two minor characters who have been in a few episodes recently but only on the sidelines.
The story was about them last night and at the beginning they both "died" very suddenly and the rest of the prog was flashbacks to their previous lives and what had been happening since they arrived on the island. they had been in league together and hatched a plan to kill a rich film director and stole some diamonds he had hidden, when the plane crashed it took them ages to find the bag that had the diamonds in, and eventually the man found the bag but didn't tell the woman. She then found out he had the bag and threw a spider at him that she knew would totally paralyse him for 8 hours, forgetting (she had been told previously) that the female attracts a hord of male spiders who then bit her. She ran out of the jungle just before collapsing to the ground and managed to say to Hurley and Sawyer that she was paralysed, but they misheard her and thought she said Paola (her boyfriend) lies and they spent the programme trying to work out what had happened. Because they were both totally paralysed and even their heartbeat's had slowed right down, they thought that the couple were dead and right at the end of the prog they buried them and you saw the woman open her eyes just as the sand was being put on top of her. Scary stuff, but a really clever story.