Lovely but less prepossessing Faye Marlowe is the mysterious client who hands Conte a diamond brooch, engaging him to retrieve an envelope. It contains evidence obtained by Savage that Marlowe's missing sister was in fact murdered, but Conte doesn't know this, or the identity of the woman who hired him under a false name. He finds out that she's part of a phony spiritualist act with arachnoid sets and get-ups (hence the movie's title). The sister, who could pass as her twin, was part of the illusion. In order to solve Savage's murder (to name just one), Conte must burrow back to 1940, using old newspaper clippings and hotel registers, to unravel the earlier killing.
Short and plot-laden, The Spider borrows, or steals, piecemeal from earlier successes (a shakedown in Conte's office harks back to Joel Cairo and Sam Spade in The Maltese Falcon, as does Marlowe's pseudonymous identity). The presence of Conte and Savage (however abbreviated) has led some viewers to chuck this movie under the rubric `film noir;' that may be stretching things. (The New Orleans locales stay strictly generic, which is a shame, as it may be the only such film set in The Big Easy, unless the even more dubious Glory Alley is admitted.) The Spider is an entertaining enough crime programmer that even a second scene spotlighting Savage would have helped mightily.