Hopalong Cassidy (William Boyd) and his friends Windy (Gabby Hayes) and
Lucky (Russell Hayden) come to Mexico at the invitation of Hoppy's old
friend Colonel Gonzalez (Trevor Bardette) - only to find out the Colonel
did not invite them at all ... and he was actually shot by Hoppy's enemy the
Hoppy promises to investigate the murder of his friend and ... seems to
do little else than romancing Janet Leeds (Betty Amann), the companion of
the Colonel's sister Anita (Jan Clayton) - much to the dismay of Lucky,
who wants to be out there, catching the killer. But of course,
Hoppy has long figured out that Anita is actually the Fox's sister, and
the only way to find his hideout is through her. Of course, in the end
Hoppy's plan works out, even if Lucky and Anita are temporarily made
hostages by the Fox's henchmen ...
It's somehow amusing to see a Western hero trying to solve a murder by
doing next to nothing, like in this film, but apart from that, In Old
Mexico is just a routine and formulaic B-Western that, while not being
essentially bad, does not hold much interest either.