This is Tom Baker's first outing as the Time Lord and after a bit of sartorial juggling, we are introduced to the staple long coat, longer scarf and floppy hat. Suffering from a bit of regenerative jet-lag, he has to get to grips with a series of robberies from the most secure of government facilities. The "Brigadier" (Nicholas Courtney) has put him under the medical care of "Harry" (Ian Marter) so hopefully he and "Sarah Jane" (Elisabeth Sladen) can discover the dastardly culprits before a very dangerous weapon is constructed and a nuclear disaster is orchestrated by a malevolent gang of folks bent on world domination. Pretty quickly, they all discover that their protagonist is a force to be reckoned with - but one that seems to have a soft spot for "Sarah Jane" - so maybe she can exert some influence and try to put the brakes on the scheming. It's good to have the whole "UNIT" team back on board for this quickly paced and frequently quite entertaining adventure tightly knitted over four parts - a format that I think worked better than the sometimes over-stretched six episode series. The ending even manages to squeeze a little bit of a moral dimension in and gives us a third member of the team for future (or past) escapades. A solid start for Baker and Marter with some fun technical effects and I enjoyed it.