They are really useful, these space-time telegraph messages! It enables the flummoxed "Brigadier" (Nicholas Courtney) to summon the "Doctor" (Tom Baker), "Sarah Jane" (Elisabeth Sladen) and "Harry" (Ian Marter) back to Earth to help investigate the total destruction of some supposedly indestructible oil rigs off the Scottish coast. Any excuse for them all to don their finest Highland garb and head north where they meet the "Duke of Forgill" (John Woodnutt) who owns a castle near the sea that is soon embroiled in this really quite superior mystery that offers us quite an unique explanation as to the origins of "Nessie". Quickly, they also discover that there's quite a bit of cloning going on and that the eponymous creatures are, of course, bent on world domination. Can the team thwart this dastardly plan? This four-parter is one of the more entertaining with a solid script underpinning a good adventure story that maybe runs little too much to Scots' stereotype - people and weather, but with Baker at his most amiably tongue-in-cheek; Sladen and Courtney again proving useful in support and Lillias Walker also quite menacing (for 5pm) as a nurse I'd sooner not encounter - regardless of how sick I was, it flows along speedily. The visual effects are also quite effective, with plenty of creative licence used on the latex and rubber delivering an original and quite formidable baddie and a good watch.