Midsomer Murders: Set 21 is another four episodes of solid British mystery, but it’s also the first set of episodes with the new DCI. In the last set, Tom Barnaby (John Nettles), decided to retire, but he also introduced the group to his cousin, who just happens to be a DCI who is transferring to Causton to take the position that Tom is vacating. So, of course, the question is, how is John Barnaby (Neil Dudgeon) like or different from his older cousin?

"Death in the Slow Lane" starts off the set with John settling into his new home just in time for a local antique car show at a prestigious boarding school. When a local DJ, and one of the show’s judges, is killed, the new Barnaby seems content with staying on the sidelines while DS Ben Jones (Jason Hughes) leads the investigation. Jones isn’t sure what to make of his new boss, especially when the DCI seems to point out annoying facts that contradict Jones’ various theories until the true events are revealed.

In "Dark Secrets," a government census-taker is murdered after discovering some secret involving a reclusive older couple and the family and artist community that surrounds them. It’s up to Barnaby and Jones to not only figure out who killed the social services investigator, but also determine what dark secrets the victim uncovered and why it led to the man’s death. We get a bit more insight into Barnaby’s character in this episode since his wife Sarah (Fiona Dolman) moves into town and we get a slightly different type of husband-and-wife banter than what was seen by the previous DCI and his family.

The third episode in the set, "Echoes of the Dead," really reveals a lot of Barnaby’s methodology and training as not only an investigator, but also a psychologist. The episode’s murders all seem to be wedding themed and that fact triggers some memories of an older investigation. Unlike many other cases in Midsomer Murders, this particular run of deaths is obviously the work of a serial killer, and it seems like there are more suspects and red herrings than normal, especially with the appearance of an ex-cop that used to work with Jones back when the DC was in uniform.

Set 21’s final episode is "The Oblong Murders" and in it, Jones goes undercover in a cult to investigate the disappearance, and possible murder, of a young lady. As he digs deeper, Jones isn’t sure what to believe about the missing person, and he isn’t sure which of his fellow new-recruits can be trusted, if any. During the investigation, Barnaby decides to start digging into an older case involving the death of an older couple on a boat. The couple owned the house that the Oblong Foundation now uses since it passed to their daughter, one of the chief members of the foundation. So, not only does Jones have to sift out what happened to the missing girl, but the pair must also work out if the initial investigation of an accidental boat explosion was not actually an accident.

As always, Midsomer Murders doesn't disappoint. John Barnaby isn’t the same character as his cousin Tom, and that is good. In fact, an attempt to simply put a new actor into the same role with the same personality would have been a crime and boring, and quite frankly, pointless. If this were a show with an overarcing storyline, then maybe something like that could be somewhat excused to preserve the overall plot, but that isn’t the case here and the new personality gives the show some interesting directions to go. I, for one, am interested in seeing how the new Barnaby works out in future cases.