Horror of Fang Rock is an excellent serial with lots of tension and some genuinely scary moments. The plot completely engorossed me throughout, and I feel that the characters are really strong and well-put-together: the dislikable characters are really dislikable and all characters seem well-motivated. Yes, some of the special effects are dated (although there is a version with updated special effects on the The Collection - Season 15 Blu-ray boxset) but, if you can overlook that, there's a really solid story here.