Ah, yes, more Sellers, more Lom.
I've read that this is often considered the drop off the cliff for the series, though there was at least one more made "with" Peter Sellers (the last I have scheduled to watch, Trail of the Pink Panther, which uses recycled and previously unused footage of the then-deceased Sellers) after this, and this one itself included Sellers. Perhaps what they meant was starting AFTER this one? I can't be sure, but this certainly felt, primarily, like a solid continuation of the now fairly long-running series. There was a slightly greater slickness and familiarity to the whole affair, with a little greater set up to some gags, and a little stronger production value (likely studios were more willing to invest money this time with that much popularity behind the preceding films), but DePatie-Freleng returned for the credits after their short hiatus for the previous film, and Kwouk, Lom and Sellers are all here and in top form for their increasingly (increasingly? is that possible?) ludicrous roles as Cato, Dreyfus and Clouseau respectively.
There is a bit of tiredness to things, a sort of "seen it" feeling, but not an overbearing one, and one which does not stop a few laugh-out-loud moments, and Edwards and company do find a new gag to focus on--Clouseau's inept disguise attempts, like a Swedish, parrot-shouldered "seadog," or a falsely rotund mob Godfather--both with Swedish and Italian accents respectively, layered on top of Clouseau's mangled French accent to a pretty amusing effect. Dreyfus' return is inexplicable after the previous film (suggestions like "prequel" abound, but it really doesn't matter) but is welcome, this time he is back in the asylum, but now being released because drug-runner (drugs? that was a bit of a strangely serious turn) Philipe Douvier (Robert Webber, who looks awfully familiar, but I'm not sure what from--probably two strangely coincidental movies--a juror in 12 Angry Men and a general in The Dirty Dozen--guess 12 is perhaps his favourite number?) has (supposedly) finally done Clouseau in, leaving Dreyfus effectively sane.
Of course, nothing of the sort has occurred and our incompetent fool of a hero continues on his way anyway, trying to take down the French Connection with said disguises and the loose-lipped advantage of his "demise" to help him. Dyan Cannon appears as Douvier's jilted lover, helping Clouseau through that inexplicable attraction he encourages in attractive women around him. In essence, it's still another live-action slapstick cartoon, complete with standard spherical black bombs with big fuses and explosions that often do little but leave people in "humorously" body-covering casts that don't hurt until squeezed and some characters or sets simply covered in carbon. If you like Sellers (and you should) and you like slapstick (and you might)--then it's not a bad choice, but nothing extraordinary.