Private Eddie (Eddie Craven) and Sally (Marie Wilson) really couldn't
have picked a worse day for starting their honeymoon. First, he is
commandeered off to Powder Island on an important mission, where women are
strictly forbidden, and when he smuggles her in nevertheless, he learns he
has to share his tent with another bloke, which of course would take all
the romance out of the honeymoon. Then though, Eddie and Sally become
involved in a murder case, which seems to involve gunrunning.
Colonel Hackett (Henry Kolker), who conducts the investigations, soon
realizes he needs help from the outside, and calls Washington to send
special investigator Bob Rogers (Cy Kendall), and Rogers gets results, and
fast, too: He finds out that Jeffries (Boris Karloff), one of the civiian
employees on Powder Island, did 8 years in prison for stealing a
gouvernment payroll on Haiti, and furthermore, Riley (Harland Tucker), the
man who got killed, was one of the key witneses against him in this case.
Rogers soon beats a confession out of Jeffries, even if that means to
overlook some minor but important details - like that it was established
that the killer wears a ring bearing his initials ...
Of all the army personnel, only Lt.Matthews (Regis Toomey) seems to be
sympathetic towards Jeffries, and even promises to help him escape ...
which puts Jeffries on guard.
And indeed, eventually Matthews reveals himself to Sally to be the
actual killer and gunrunner too, and he tries to take her as
hostage to be able to leave the island ... but in the end is stopped by
Jeffries, who this way re-establishes his good reputation, even if he had
to catch a bullet for that.
Even if the plot seems at times a bit farfetched, and the killer is to
spot early on, Invisible Menace is a nice B-crime-thriller, with
the ever-dependable Boris Karloff carrying large parts of the movie with
ease and Eddie Craven and Marie Wilson loosening up things considerably as
the foiled honeymooners. Fun.