A lot has happened in the two years since Sherlock Holmes (Benedict Cumberbatch) seemingly leapt from a building to his untimely death in the Sherlock season two finale ‘The Reichenbach Fall.’ For John Watson (Martin Freeman), those two years have culminated in him finally settling down with his cozy GP job, his nice new home, his experimental facial hair and his lovely fiancée-to-be Mary Morstan (Amanda Abbington).

For Sherlock, the years haven’t quite been so kind. The third season finds the consulting detective shaggy-haired and bloody, being tortured for information in a Serbian prison. To add insult to injury, a bird has pooped on his gravestone. After finally managing to dismantle the last of Jim Moriarty’s (Andrew Scott) criminal network, Sherlock is called by to London by his brother, Mycroft (Mark Gatiss), to prevent an imminent terrorist attack, conveniently helped by the fact that his name has recently been cleared of all the crimes that Moriarty attempted to pin on it.

There’s a lot of exposition to cover in this episode, though that’s helped by the 90 minute running time. ‘The Empty Hearse’ plays catch up with most of the key characters from the series, some of whom have moved on a great deal in two years while others… haven’t. Scotland Yard’s forensic expert Anderson has perhaps undergone the most radical change of heart, having started a Sherlock Holmes fan club and lost his job as a result of his insistence that the detective faked his own death. Jonathan Aris’ portrayal of Anderson’s somewhat unhinged obsessiveness is both funny and a little disturbing, and the audience is definitely left wondering what part Anderson might play in the rest of the season arc.

Despite the title, ‘The Empty Hearse’ is a surprisingly light-hearted episode that avoids some of the dreary or melodramatic pitfalls that could have plagued scenes like, for example, Sherlock’s revelation to John that he is still alive. Definitely a highlight of the episode, this moment cheerfully straddles the border between heart-rending and hilarious as the detective handles the situation with his usual grasp of sensitivity and tact.

Some of the humor can be a bit hit and miss (the show’s running “no homo” gag really needs to die), but even the weaker jokes have their own kind of charm. Cumberbatch and Freeman’s strong screen chemistry is the cement that holds Sherlock together and it shines brightest when both actors are engaged in volleying matches of dialogue, but the supporting cast hold their own as well. Abbington in particular is a welcome addition as Mary, whose relationship with John comes across as very sincere and comfortable, and who acts as a mediating influence in the turmoil of Sherlock’s return.

When discussing the upcoming third season of Sherlock on a recent SR Underground podcast, one of the complaints that came up was that the witty dialogue and excellent performances are not quite matched in quality by the actual mysteries of the show, and that’s a criticism that certainly applies to ‘The Empty Hearse.’ There is a bit of a head-scratcher regarding a train passenger who mysteriously disappears from his carriage between stops, but the terrorist plot is somewhat dwarfed in an episode that is largely concerned with Sherlock’s return and the re-establishment of character relationships.

This may have something to do with the fact that ‘The Empty Hearse’ definitely feels like a ‘Part 1′ more than either of the other season openers. Rather than being a purely standalone episode, much of the running time is dedicated to setting up characters and clues that will presumably become more prominent in the next two episodes of this season. One unfortunate side effect of this is that the episode’s plot and structure feels rather loose and meandering – more like a collection of minisodes than a cohesive whole.

Nonetheless, any concerns that Sherlock might have lost its magic during the hiatus should be allayed by this generally strong season premiere. ‘The Empty Hearse’ might not rank as the best episode so far, but it makes one hell of a good entrance.

Sherlock returns to PBS with ‘The Sign of Three’ on Sunday, January 26. You can check out a preview of next week’s episode below: