Doctor Who 101: A Viewer's Guide To The Classic Series - Part 2
An introductory viewers guide to the classic series, here is a list of important episodes: the essential, the exceptional, the merely expository (as, sadly, the very best episodes and those that are important to the overall series continuity are not always the same), and the execrable. You can find Part 1 here: Comments, criticisms and contrary opinions from other veteran viewers are, of course, welcome. But if you're one of those fans who started watching Doctor Who when it came back in 2005, or who came onboard only as recently as the Tennant or Smith eras, who's curious about past Doctors, past episodes, and the long and winding mythos of a series that has become an international phenomenon, but doesn't know where to start, this guide is for you... 
How does a show that had become a national institution in Britain, and a cult phenomenon worldwide, recover after losing the actor who had come to define both the series and its lead character for so many in its viewing audience...? You try something completely different... As played by Peter Davison, the Fifth Doctor presented a stark contrast to Tom Baker's towering, authoritative, and truly alien Fourth. Tentative, introspective, soft-spoken, easily flustered and even, at times, indecisive, the Fifth Doctor was, in fact, very different from all of his predecessors. Whereas the previous four incarnations had appeared as older men radiating a childlike wonder, and occasionally, a spark of childish mischief, the Fifth Doctor, despite his youthful physical appearance (at 29, Davison was the youngest actor yet to play the role), seemed stoic and ancient, quietly burdened by his centuries of experience, and the weight of the responsibility he felt for his companions. Though occasionally buoyed by a "reckless innocent" charm and a dry, understated wit, the Fifth Doctor remains perhaps the most serious and sincere Doctor to date. Davison was already a popular UK television actor when he was cast in Doctor Who. Both the BBC and producer John Nathan-Turner felt that Davisons popularity, as well as his radical contrast to Tom Baker, would help sustain the series after Baker's departure. Though happy to accept the role, Davison has since admitted that he felt somewhat miscast, and perhaps he allowed that feeling of uncertainty to inform his unique, softer take on the character. Regardless, the series continued on, almost as popular as ever, and despite any misgivings he may have had, many a Doctor Who fan today claims Davison as THEIR Doctor. The Essentials:
Earthshock (Season 19, Episode 6)
Aptly titled, Earthshock is one of classic Doctor Whos darkest and most jarring stories. The penultimate serial of Peter Davisons first season, it seems impossible that, more than thirty years on from its initial broadcast, even a casual fan would be unaware of its most significant and striking reversals. Even so, they are executed with enough force and weight to retain a great deal of their impact, and they are pivotal to the development of the Fifth Doctor. Davison had, by this time, settled comfortably into the role, and his Doctors vulnerable warmth serves to make Earthshocks jolts that much more affecting. Calloused critics have complained in retrospect about the perforated, paper-thin plot, and while they have a point, the productions stylish intensity and vigorous pacing carry you along without leaving much time for dwelling on any narrative flaws until after the ride is long over. Regardless of any shortcomings, Earthshock is a landmark episode that makes for startling, enthralling viewing. Its unprecedented, traumatic final moments remain iconic in the series, and would haunt the Fifth Doctor for the remainder of his tenure. Caves of Androzani (Season 21, Episode 6) 
Considered by many to be the finest episode of the classic series ever made, Caves of Androzani, if not quite so superlative, is certainly a powerful, gritty, intense story, and the perfect swan song for Peter Davisons Fifth Doctor. A harsh, ultra-modern tale that drops The Doctor and his shiny, new companion, Peri (Nicola Bryant), into a minefield of amoral conflicts relating to gun-running, the drug trade, and political corruption in a distant planetary system, it manages to compellingly follow the individual narrative threads of multiple characters on multiple worlds, without losing an ounce of urgency or focus, as it races towards its breathless, tragic finale. The near-saintly nobility of Davisons Fifth Doctor stands in vivid contrast to his harsh, morally grey surroundings, and is given its fullest expression in his final act, a self-sacrificing gesture that provides an uneasy atonement for his failures in Earthshock. In an unusual turn, the serials last few seconds memorably introduce us to the newly minted Sixth Doctor, inciting both curiosity and some trepidation about whats to come. And if all thats not enough, Caves of Androzani is the serial that finally explains why the Fifth Doctor spent three years with a celery stalk affixed to his lapel The Exceptional
Mawdryn Undead (Season 20, Episode 3)
A brilliantly inventive and absorbing story, Mawdryn Undead also has quite a lot going on. As a part of Doctor Whos commemorative 20th Anniversary season, it not only brings back some familiar friends and foes from episodes past, but also introduces an intriguing new companion, AND serves as the beginning of a trilogy that would form a mini-arc at the seasons heart. Not that any of that has any significant bearing on the storys main events, in which the Doctor is reunited with an amnesiac Brigadier in contemporary England, but separated from his companions who are literally in the right place at the wrong time, while an alien scientist attempts to hijack the TARDIS and learn the secrets of regeneration. Its not as convoluted as it sounds. Or maybe it is. But its also a smart, satisfying serial that capably exploits the narrative possibilities of time travel while exploring the existential perils of attempting to artificially extend life. While some may question the wisdom of recommending a story that references past episodes (many of which are not included in this guide), most will say its outright madness to recommend the first part of a trilogy, while ignoring the latter two (though, the truth is, theyre kind of a letdown). But Mawdryn Undead is intelligent, involving entertainment that, in and of itself, has a great deal to offer to both longtime fans and newcomers, alike. The Five Doctors (Between Seasons 20 and 21) 
A special episode produced in honor of Doctor Whos 20th Anniversary, you can find a lot of fault with The Five Doctors. For starters, its really more like The Four Doctors, since Tom Baker declined to participate, and thus appears only through the creative use of footage from the never-completed Season 17 story, Shada. And really, its more like The Three Doctors, since William Hartnell had died in 1975, leaving the First Doctor to be played by Richard Hurndall, who does a perfectly adequate job, but still Its also rife with the sort of continuity problems inherent to multi-Doctor stories and, upon close examination, its flimsy plot is really just an excuse for a series of vignettes that pay homage to the history of Doctor Who. So, yes, you could find a lot to criticize. The question is, why would you? Because for all its flaws, The Five Doctors is fun, funny and exciting from end to end. More a celebration than a story, it shows off the differing personas of all five (or four or three) Doctors, allowing them, as well as their companions and numerous adversaries, ample screen time before bringing them together for a climax that, if not overly significant to the series mythos, is at least in keeping with the twentieth seasons themes of life, death and immortality, and manages to be surprisingly effective and affecting. A vast improvement on the 10th Anniversarys The Three Doctors, its a massively entertaining adventure and a fitting tribute to the show and its history. Just dont think about it too hard The Expository
Arc Of Infinity (Season 20, Episode 1)
As exposition goes, Arc of Infinity is not really necessary viewing, at least when it comes to gaining a basic understanding of Doctor Whos overarching mythos. Sadly, it is not especially rewarding viewing, either. However, being a Gallifrey-set story that features the return of Omega, and the ascendance of the Doctors former teacher, Borusa, to the Presidency, it functions both as a sequel to the 10th Anniversary episode, The Three Doctors (to say nothing of Season 15s Invasion of Time), and as a prologue to The Five Doctors. Once again, the Gallifreyan veil of aristocratic dignity is lifted, revealing the morass of bureaucracy and corruption at the hearts of Time Lord culture. References to past companions and adventures abound. There are even some unintentional nods to the future (theres something strangely familiar about that witheringly arch Commander of the Guards). As the endlessly put-upon Doctor, Davison gives a sympathetically patient performance, and in the serials fourth and final episode, hes even given the chance to remind us just how versatile and affecting he can be. But mostly, Arc of Infinity is a lot of squandered potential, offering context without content and functioning best as a bit of connective tissue. The Execrable
-->-->Davisons three seasons boast some truly exceptional episodes, but there are also quite a few missteps and some outright stumbles (e.g. the latter two parts of the aforementioned trilogy begun by Mawdryn Undead: the interminable Terminus and the lackluster Enlightenment). The worst offenders are the disastrous Time-Flight, the floundering Warriors of the Deep, and the searingly silly Planet of Fire.
A Few Extras:
Frontios is a first-rate episode that almost made the Exceptional list. And The Visitation is routinely named by fans as one of Davisons best.