Close to 30 years later, it’s hard to imagine the impact that Deadly Assassin must have had upon Dr. Who viewers the first time it aired.

Most of us who grew up on Who watched in the post-Deadly Assassin era, so it’s hard to imagine the impact this must have had on Who fans back in the mid-70s when Robert Holmes’ classic story first aired. Up until this point, the Time Lords had been presented as a powerful, almost omnipotent society that seemed to always be in control of things. There were never hints of any types of class struggle or a hierarchy of houses or even a hint that any of the people within the system could be corrupted (obviously seeing the Doctor and the Master, we knew there were those who were discontent with the system, but until now we’d always seem a unified and powerful front both in War Games and Three Doctors).

Deadly Assassin changes all of that in four short episodes.

The Doctor is summoned home to Gallifrey by powerful visions of the assignation of the Lord President of the High Council. The Doctor’s return is not treated as a good thing by his fellow Time Lords, many of whom see him still as a rebel and possibly the person there to assignate the Lord President. The Doctor quickly becomes embroiled in the plot and tries to stop the assignation, only to fail and be accused of the crime himself. The rest of the story follows the Doctor as he attempts to solve the mystery, even to the point of entering the Matrix to find the real traitor and the real mind behind the plot. On paper, it sound like a fairly standard Who story—Doctor arrives in a place, Doctor gets accused of a crime he didn’t commit, Doctor solves the crime and finds the real culprit. But along the way, we get so much more than that.

Robert Holmes gives Who fans the first real look at Gallifrey. Before this, we were superficially exposed to the Time Lords home world—seeing a trial room in The War Games and a command center in The Three Doctors. Here we see the internal workings of Time Lord society. It’s a system very much based on class and which house you belong to. We find out the Doctor belonged to a rather esteemed house and that his departure caused a lot of ripples. We even find out that not all the Time Lords are aware of the Doctor’s departure and his meddling in time and space, as we see in the conversation with Runcibal at the Panoptican. We also find out that the Time Lords can be just as corrupt as the Master himself and some of them are even power-hungry enough to cast their fortune in with our favorite villain from the Pertwee years.

It’s a bit shocking, really. The Time Lords are no longer pillars of morality and justice. They have become more complex—and, thus, some of the mystery surrounding them has been taken away. Robert Holmes knocks the Time Lords down a few notches and forever changes who stories about Gallifrey are told.

In many ways, the changes in The Deadly Assassin are as radical as the changes that FOX TV movie would attempt years later.

But yet, these changes are more accepted by Who fans and not as radically debated or decried among the Who community.

Why is that?

I think a large part of it is that Holmes took seeds that were sown and while he did run with them in a new way, there were hints this was coming. Deadly Assassin is one of those stories that makes you re-examine all the stories that came before and all those that come after it. Holmes does come from out of left field with the story, but not so far as to strain viewer credulity.

And while all of this is important to Dr. Who, Holmes never loses sight of the fact that in order to get these points out there as part of the Who canon, you’ve got to tell a great story to go along with it. Deadly Assassin is a great story. It’s full of politician intrigue, well done dialogue, suspense and drama. And it must have hit some nerves with Who fans since it’s infamous for the violent outcry by one Mary Whitehouse over the apparent violent content—especially in the Doctor’s struggle in the Matrix. The story is four episodes of great storytelling with the usual dark flourishes by Robert Holmes and a darn good story along the way. In many ways, Deadly Assassin is the best 4th Doctor story that Robert Holmes delivered, though it can be argued that Ark in Space is as good in its own way.

But along with the intrigue, there are ties to the past - with the Master coming back to seek his revenge upon the Doctor. This plotline feels like a plot the Master would come up with - one that is layers within layers and designed to trap the Doctor. You get the feeling like you did during the Delgado era that the Master’s plots were complex and complicated in an attempt to trap the Doctor - but yet, the Master would sometimes miss the blindingly obvious details that would allow his plan to succeed. We also see the beginning of the Master’s half-baked ideas that become so prevalent in the JN-T years with Ainley. The Master has a gratutious scheme and is willing to do whatever it takes to carry it out and bring himself the things he wants - power and the destruction of the Doctor, but only by first humiliating his long-standing enemy.

The Deadly Assassin is many things. It’s a violent story of good vs. evil. It’s an examination of the Time Lord society in a new way. It’s a four-part adventure that seizes you by the throat and never lets go. And most of all, it’s a darn fine story. Outside of Caves of Androzani, this may be Robert Holmes’ masterpiece of Doctor Who. And saying that about a writer of Robert Holmes’ caliber is a high compliment indeed.