I listened to this just under a month ago and it has not left my head since - and I rarely relisten to stories after hearing them once. This story is like if you rolled a haunted house story, Pet Sematary and an "I Know What You Did Last Summer" kind of slasher film into one. One word - gothic. In terms of pure horror atmosphere, it doesn't get better than this. Admittedly, it took a while for things to click properly on first watch - the mystery of what the five academics are doing on a spooky island in a spooky mansion isn't made clear until the second half, and exactly what they were doing and how is admittedly somewhat difficult to wrap your head around. But when it clicks, it clicks. "Temporal experiments leading to the creation of a psycho zombie serial killer girl who gouges people's eyes out" is an all timer concept for a Who story.

10/10. Will be relistening a lot in future.