This fifteenth series of Time Lord adventures finds the "Doctor" (Tom Baker) and his companion "Leela" (Louise Jameson) materialising on a remote rock where the local lighthouse is experiencing some mysterious goings on. Might a recent meteor strike and the freezing fog that is descending on them have anything to do with it? Well it might have something to do with a shipwreck shortly afterwards that sees a load of rather untrustworthy (and slightly flakey) posh folks seek shelter in the building that was previously the home of "Ben" (Ralph Watson) and his two colleagues. Suspicions mount even more when the power supply to the building - and it's light - starts to become erratic, the bodies start to pile up, and it might be time to batten down the hatches before what's really out there makes it's attack. The slightly claustrophobic Victorian settings work well here as do the misty sets and the engaging efforts from a solid and recognisable supporting cast delivering a story that's neatly packed into four episodes and is quite funny at times, too.