The Rescue

'The Rescue' is unusual in that it serves almost exclusively as an introduction for Vicki; this is unusual for the series, since in future new companions are generally introduced as characters playing some role in the overall plot who join the TARDIS at the end of the story, rather than being the primary focus of the plot. However, this is of course the first time that a new companion joins the TARDIS crew since the start of the series. 

Although Susan departed in the previous story, the actual dynamic of the crew does not yet change, since Vicki fills her role almost perfectly. True, she is more independent and headstrong than Susan, probably as a result of the death of her parents and her near solitude on Dido, and O'Brien is a better actress than Ford, but Vicki almost immediately replaces Susan in the Doctor's affections, obviously reminding him of his granddaughter from the start. Her immediate idolization of him completes the effect. Nevertheless, she is less annoying than Susan, which can only be a good thing, and generally seems more fun. She deserves extra sympathy points for her background as well, since losing her family and being stranded on a strange planet with (apparently) a hostile alien must be traumatic to say the least. As an introduction for Vicki then, 'The Rescue' works perfectly.

At only two twenty-five episodes in length, 'The Rescue' has little time for development of the other regulars, but Whitaker's grasp of characterisation, previously seen in 'Inside the Spaceship', stands him in good stead. The Doctor is obviously affected by Susan's departure, falling asleep and missing materialization, and just seeming generally vulnerable in the first TARDIS scene. His transformation into purposeful guardian after meeting Vicki is wholly believable and he quickly becomes his usual indomitable self when dealing with Bennett. Ian is pretty much sidelined, but Barbara gets something to do even if that something is slaying Vicki's pet, Sandy. Although this is clearly not her finest moment, it is presented in such a way as to make it understandable, since she reacts instinctively to protect Vicki and the Doctor is quick to defend this, noting that he would have probably acted the same way in Barbara's position. At the end of the day, Barbara's reaction is a believable one; most people confronted with a large fanged, snarling alien monster would probably have shot it on sight if they had a weapon to hand. 

The Bennett/Koquillion plot is sparse, but again functional, since it provides a token threat to frame Vicki's introduction. Admittedly Bennett is not a very memorable villain, but he serves his purpose and is competently acted, never quite becoming the frothing madman that lesser writers might have made him and instead coming across as a calculating murderer, which is always more believable. 'The Rescue' is mocked in The Completely Useless Encyclopedia for being a murder mystery with only one suspect, but in all fairness Vicki is unlikely to doubt the story presented by her brusque "mentor", since she is naturally more likely to believe the story of someone she knows, especially with an alien race she knows nothing about on hand as potentially more likely suspects; in effect, Bennett exploits fear of the unknown. Besides, once the Doctor meets Vicki, he almost immediately discovers Bennett's guilt anyway. 

There are two aspects of 'The Rescue', which are IMO a failure – the Didoi, when we briefly see them, instantly vie with the Thals for the title of Doctor Who's most boring alien race so far, appearing as they do as humans in silly costumes. Admittedly, there isn't much time to develop them further, but at least if they had actually looked like Koquillion (whose costume, face and claws included, turns out to be ceremonial robes stolen by Bennett) they would have been marginally more interesting. The second failed aspect is the cliffhanger, which is rubbish – the Didoi are supposedly a peaceful race, yet have a clichéd death trap outside their hall of justice, which clearly exists only to threaten Ian at the end of episode one. This might be more forgivable if the trap was less convincing; as it is, the blades that supposedly push Ian towards the edge of the chasm are visibly far apart enough to allow him to simply stand between them until they retract without being scratched. Sandy at least is used as more than a potential threat waiting in the chasm, since he turns out to be Vicki's pet and is killed by Barbara, as mentioned above.

So in summary, 'The Rescue' is a flawed but functional introduction for Vicki. It may not be memorable for much else, but it isn't pleasant enough and its length makes it a welcome respite from the usual four- or six-parters.