A freak accident leaves two dangerously unstable spacecraft locked together, and a horde of monsters unleashed on their passengers.
This time, it's not the TARDIS that dematerialises in the wrong place for a change, but a star cruiser that comes out of warp and crashes headlong into a scientific venture aboard the ominously named "Hecate". Their distress beacon is what brings our travellers to the rescue, and quickly they are embroiled in some intra-temporal shenanigans that release the "Mandrels" from another dimension onto the ship who begin eating the economy passengers! It's also a bit worrying that there is a drugs smuggling operation going on here too - and, of course, the "Doctor" (Tom Baker) and "Romana" (Lalla Ward) are initially suspects before, well you know the drill by now... I don't recall "K9" ever needing his laser quite so often before, but phew are they glad he is there as this mystery becomes quite (tea time) violent. This isn't really one of the best stories and the cast - especially "Prof. Tryst" (Lewis Flander) with his seriously ropey Eastern European accent and David Daker hamming it up as the captain don't really do much to help pad out what is a really quite thin plot. There are times when I'm sure Baker looks like he's laughing... Not the best, maybe the best of the worst?