Like many of the less-memorable episodes of this series, especially from its earlier seasons, "Two Doves and Mr. Heron" is noteworthy more for the presence of some of its guest stars than for a riveting plot. John Ritter, shortly to get a role on "The Waltons" as Rev. Fordwick (before hitting the really big time on "Three's Company"), plays a street hustler wearing a costume that seems to have come from a community theatre adaptation of "Oliver Twist"; and Dianne Hull, a less well-known actress, is his girlfriend who happens to have a connection with Danny Williams.
Their misfortune is to run into an even more sleazy character played by the equally-recognizable Vic Morrow. Unlike Ritter, whose triumphs were mostly still ahead of him, Morrow was coming off of five years as Sgt. Saunders on "Combat" during the mid-1960s, which would turn out to have been his biggest success; bouts with alcohol made him less reliable as an actor -- which is unfortunate, because Morrow always brought a rare intensity and power even to a somewhat thankless role like this one. The episode suggests that his character, "Mr. Heron," might be a closeted homosexual, in addition to being an embezzler; but perhaps that's just as well, as those kinds of subterranean motivations can only add to a Morrow performance.
Ritter's character, if anything, is even less admirable than Morrow's. He's a glib and self-confident panhandler, who also says all the right things to string along his hippie-like girlfriend; the audience can see right through him even if she can't, and it's mostly an obnoxious role. Indeed, at a critical moment, Ritter's character doesn't do the heroic thing (though he redeems himself somewhat later on).
Unlike some of the stand-out episodes this season -- including one featuring a hilltop sniper; a decades-old murder mystery; a two-parter with Wo Fat; and a serial killer who paints his victims like a prostitute -- this episode provides only routine challenges for our Five-O characters. Chin and Steve, for instance, seem to figure out that "Mr. Heron" is up to something with surprising ease; and, if anything, this is one of those episodes where Five-O's involvement is almost a distraction from the most interesting story -- namely, the relationship among the criminals. Even the avian play-on-words in the episode's title seems a bit odd, because early in the episode there's a surprisingly violent act by one of the two "doves," and anyway, "Mr. Heron's" name turns out to be just a pseudonym.
What remains are very good performances by two actors, Ritter and Morrow, who were always interesting to watch, especially Morrow. Both are linked not only by this modest episode of Five-O, but also by the suddenness of each of their deaths (each in his early fifties) -- Morrow barely a decade later in a tragic accident on the set of "Twilight Zone: The Movie" and Ritter from an undiagnosed aortic aneurysm. So, despite the relative mediocrity of "Two Doves and Mr. Heron," it's at least enhanced by the presence of two guest stars who are remembered today for bigger things, and who were taken from us much much too soon.