I have previously cited this story as perhaps the worst Batman story of the Silver Age. To give you an idea, back when I was really trying hard to push my run of Batman issues backwards, I stopped at #148 because I could not see paying $1.00 or so (at the time) for a comic with such a ridiculous cover.
The opening story is the Plants of Plunder. Batman and Robin encounter some crooks who use seeds from alien plants to commit crimes:
As Batman and Robin chase them, the crooks use another fantastic plant:
It turns out that they have stolen them from an alien who temporarily lost his memory, but regains it here:
It turns out that he was an alien farming scientist who came to Earth to try out his seeds here and got knocked out when the plants grew too quickly.
Comments: Dull and predictable, with a gaping plot hole. The alien initially shows up disguised as a human at Commissioner Gordon's office. He's already got amnesia. So how does he wind up back at the crooks' hideout at the end of the story, where he hits his head and regains his memory?
The Secret of Mystery Island is a pretty straightforward Treasure Hunt. There were a fair number of these stories in Batman over the years. The basic plot is that a dying rich man leaves a clue to the secret location of his fortune, with that clue leading to another clue. In this case, the dying man is an architect (and criminal mastermind) named Briggs, and his henchman Catlin is seeking the treasure, which Batman and Robin manage to recover.
Comments: Although I usually like these types of stories, this one is poorly executed, with clues that seem forced. Catlin looks into one eye of the Buddha, and assumes when he doesn't find anything that Briggs had lied about a treasure. But he doesn't look into the other one, which does hold the clue, which Batman promptly solves. In addition, the story lacks a needed element, which is that there should be some animosity between the dying man and his treasure seeker; otherwise, why put the latter through the wringer of the treasure hunt? But there is no indication of that here:
The cover story is the grand finale. Now, as background, Mort Weisinger had been having some success at the time with stories featuring "Superbaby", that is, Superman as a toddler. It's important to remember that in the Silver Age (as compared to present continuity) Clark Kent always had his super-powers, even as an infant, so that Superbaby could fly, was invulnerable, could lift incredible weights, etc., so his main limitation was that he thought like a baby.
Well, this was not going to work for Batman, clearly, who had no superpowers aside from his brilliant brain. And so the story flows fairly obviously, if ridiculously from the simple idea of regressing him physically but not mentally. Batman and Robin raid the hideout of Nails Finney, where they discover also the "renegade scientist" Garth, who has a surprise for Batman:
No, not the dreaded "eerie ray of light"! Well, before you know it, Batman has shrunk down to Oshkosh Bgosh size:
Due to a "flaw" in the machine, despite being turned into the Diapered Detective, Batman retains his adult mind and strength. He quickly trains to adjust to his new body, makes a few revisions to his costume and:
Later, he captures some crooks on a rooftop by using a large balloon to float him up there, since he doesn't weigh as much as he used to. But of course that makes this scene highly unlikely:
But now it's time for a secret identity crisis, as Kathy (Batwoman) Kane comes calling to see if Bruce Wayne is wearing short pants these days. But she leaves in a huff when she sees his silhouette kissing another woman. Quick thinking, Batman!
Batman and Robin find Garth's hideout, but when some henchmen come running up to help prevent Bat-Baby from reaching the machine:
And eventually Batman regains his normal size by reversing the ray.
Comments: You can argue that this one is played for grins, but it delivers more groans instead. Overall, this issue is the epitome of the worst of the Jack Schiff era.