The fact that Barrie leaves the show just confirms the Classic status of this episode megastyle.
There are some real emotional scenes (unnaturally for RD) throughout. The episode is essentially a standard hero tale but in reverse. The middle of the tale - the (new) journey (for Rimmer) starts is at the end. The novices first step into his new journey.
The start of the tale, where the hero life is shown and turned upside down, without knowing if he wants to take the path to being hero, is in the middle. The classic master imparts the facts of his existance and duty to the novice.
The end of the tale (or an alternate dimensional instance of it) occurs at the beginning. Where the hero is dire straits escape his predicament, saves the girl and escapes....
In this way, the episode bravely turns the plot method on its head and captured my imaginiation. Very cleverly done. Its a worthy plot with screenplay, dialogue and gags to warrant a series classic on its own. The story in itself is sharp and moves along very quickly, never stagnating. As you can imagine the main characters are Rimmer and Ace, both played by Barrie. The dialogue works wonderfully and you get the impression of two competing personas, but essentially belonging to the same univseral entity. Lister has a small part in helping Rimmer make the right decision, who throughout causes conflict in that he doesnt want to take up his destiny. Its one of the few times that Dave is actually nice to him and forms a poignent moment as Barrie prepares to leave.
As Ace slowly dies, Lister convinces the rest of the crew that it was really Rimmer whose HLight failed, as he has badly taken on the appearance of Ace. Once Rimmer assumes the role there are a number of continunity errors in the execution of the screenplay as the crew appear to "know" or guessed that old Rimmer has become Ace at least in the dialogue.
The ending however, is one of the most moving acts to have ever been conceived. With so much mediocrity heaped on the shoulders of the gormless Rimmer, no one can fail to be awestruck to find out that it was always his destiny to become an Ace sooner or later. The sheer scale and scope of graveyard dedicated to Rimmer was gut-droppingly moving.
I was simply awestruck again - and its this sequence of revelations put into context against Rimmers past that just makes this episode a perfect 10.
Note: I believe that if you check previous episodes where Ace appears thats why he takes a special understanding for the hapless Rimmer, because he knows that one day, that ugly duckling will become the legend! (at least in some of the episodes)!
Simply awesome. Unmissable.