Frank Raymond (likeable Jon Hall), who's the grandson of the invisible man, uses his grandfather's invisibility formula so he can sneak into Germany as an undercover spy in order to thwart the Nazis and romance beautiful female double agent Maria Sorenson (the charming and elegant Ilona Massey).Although director Edward L. Marin relates the inane, but still enjoyable story at a snappy pace and maintains an amiable lighthearted tone, he alas overdoes the goofy slapstick humor, with the portrayal of the Nazis as bumbling buffoons coming across as both annoying and embarrassing. The special effects are strictly hit or miss: The invisibility stuff holds up pretty well while the painfully obvious miniature planes leave a lot to be desired. Fortunately, there's a trio of excellent villains who ensure that this movie remains watchable: Peter Lorre as oily Japanese weasel Baron Ikito, Cedric Hardwicke as the smoothly sinister Conrad Stauffer, and J. Edward Bromberg as the smarmy Karl Heiser. A pleasant diversion.

Jon Hall plays Frank Raymond, the grandson of the Invisible Man, who has changed his name from Griffin to Raymond and runs a print shop in hopes of avoiding people looking for his grandfather's formula for invisibility. When Axis agents led by the nefarious duo of Stauffer (Cedric Hardwicke) and Ikito (Peter Lorre) show up and threaten Raymond, he decides to become the Invisible Man and spy for the Allies.The least of Universal's Invisible Man films but still enjoyable. The continuity's a little sloppy. Frank is said to be the grandson of the original Invisible Man, also named Frank Griffin. But the original was named Jack. It was his brother from The Invisible Man Returns that was named Frank. Plus the original Invisible Man died without kids, unless we're to believe his fiancée in the first movie was pregnant. Anyway, it's probably best to assume Frank Griffin took credit for his brother's discovery...or, you know, don't bother explaining it at all because it's really not that important.Hall is fine but his character can be irritating at times. The film's worst scene is where he pranks Nazi Karl Heiser (J. Edward Bromberg). The whole scene is a juvenile attempt at laughs that fails badly. Bromberg's character is a perfect example of the movie's main flaw: the out of place comedy within the darker wartime plot. For the most part, Heiser is a joke and treated like Schultz from Hogan's Heroes. But then there are scenes where his darker side comes through that makes the comedy parts a poor fit. Ilona Massey looks great but her character seems to exist just to fall for Hall, even though he treats her pretty crappy. The climax of the movie plays like an action serial with the Nazis pursuing Hall and Massey as they try to escape by plane. What happens next I won't spoil but it's unintentionally silly.Two characters that actually do work are the evil Stauffer and Ikito, played by Cedric Hardwicke and Peter Lorre. These two are the best part of the film, providing a real menace to the hero. Lorre's Ikito is an especially evil character. He begins the film by threatening to chop Frank's fingers off and later ingeniously (and sadistically) catches him with a net lined with fish hooks! These great actors own every scene they're in and it's worth seeing the movie just for them.

"Invisible Agent" was one of the few Universal "series" horror films I hadn't seen until now. It's basically a good concept for a film — turning the Invisible Man loose on the Axis and a formidable set of German and Japanese villains including Sir Cedric Hardwicke (just as despicable here as he was in "The Invisible Man Returns"), Peter Lorre (who just about steals the entire show) and Keye Luke. Lorre doesn't wear any "slant-eye" makeup to turn himself Asian, but he hadn't as Mr. Moto either and he's just as believable here. Still, there are a number of missed opportunities in this movie. Why is Jon Hall's character depicted as the grandson, not the son or nephew, of the original Invisible Man? (That would have made sense if the 1933 film had been set in the 1890's, when H. G. Wells wrote the source novel, but it wasn't.) More importantly, why did Curt Siodmak omit the key plot device that the invisibility formula turned its user into a raving megalomaniac as a side effect? One could readily imagine the Nazis trying to recruit the Invisible Agent to their side as the drug took hold of him and he started sounding like them! Still, it's a fun movie and Ilona Massey's character is appropriately morally ambiguous -- though she must have wondered about the direction of her career: she'd been brought over to the U.S. by MGM in 1939 to replace Jeanette MacDonald as Nelson Eddy's co-star in the elaborate operetta film "Balalaika," but just three years later here she was at Universal making movies like this and "Frankenstein Meets the Wolf Man."

Of the "Invisible Man" series made by Universal, I was only familiar with the first two (both of which I'll rewatch again presently) - the James Whale original being one of my all-time favorites.Ever since it was released as part of the "Legacy" set, I had mostly read negative opinions about this film - and even Leonard Maltin gives it a pretty low rating. However, I was very surprised by how much I enjoyed it! True, the leads are rather bland (why on earth is Ilona Massey credited before Jon Hall?!) but, then, INVISIBLE AGENT has a formidable trio of villains - Peter Lorre, Sir Cedric Hardwicke and J. Edward Bromberg - going for it (who even make Curt Siodmak's script sound better than it is). Besides, I must say that I'm a sucker for both WWII and espionage movies, so that's a big plus as well...which, I guess, means that it isn't really a horror film and that The Invisible Man is the hero! Oh well, you can't have everything!John P. Fulton's still-impressive special effects (exposed a bit here by the extra clarity of the DVD transfer) deliver the goods and, all in all, the film made me keen to get to the remaining titles in the series.