The aptly-named Gruesome (Boris Karloff) has recently been released from prison, and has made his way to a bar in the city called The Hangman's Knot where he meets an old friend, Melody the piano player (Tony Barrett). Melody is delighted to see him, and immediately leaves the bar to take him to a hideout of a few acquaintances of his who are planning a crime. Left in a lab while Melody consults with them, Gruesome is told not to touch anything yet cannot resist going over to the safe; he doesn't find any money, but he does find a test tube filled with a mystery substance. Once he gets a sniff of it, however, he feels woozy and stumbles out into the night...
The last of RKO's Dick Tracy films, Ralph Byrd returned (on his way to starring as the detective on television) but this time they had a proper star to take the villain role: as Tracy's right hand man Pat Patton (Lyle Latell) points out, they might as well be dealing with Boris Karloff. For this reason, this instalment is the best of them, and has a grittier feel thanks to a willingness to bump off the characters along with a lightly science fictional element that makes it stand out. This is because the test tube Gruesome got a noseful of contains a special nerve gas that freezes its victims, although it takes a lot longer to work on him - he ends up back at The Hangman's Noose (which has a neon sign of an, erm, hangman's noose in the window).
As a sop to Karloff's horror pictures, he ends up in a corpse-like state thanks to the gas and his body is picked up by Patton who thinks he's a drunk, or he does until he gets him back to the station when rigor mortis appears to have set in. Cue a scene with Patton writing up his report with Gruesome coming back to life on the trolley behind him, creeping up and knocking him out with a blow to the head. After that, we're pretty much in thriller territory as Tracy tries to find out who the body was and why he's escaped. He has his answer when a bank robbery takes place the next day, which is witnessed by his plucky girlfriend Tess Trueheart (Anne Gwynne).
What she sees while safely in the phone booth is the staff and customers of the bank freezing thanks to the nerve gas, which is presented on screen by the time-honoured fashion of stopping the film, or at a stretch asking the actors to stand stock still if another actor has to move around them. As if robbing the bank wasn't enough, Melody shoots dead a guard, so this is obviously serious and Tracy has a race against time on his hands to track down the gang, not to mention appease the dogged reporter trying to file his story before two o'clock. In truth, Dick Tracy doesn't meet Gruesome until the last five minutes of the film, and Karloff doesn't feature as heavily as perhaps you would like, but this is pacy and amusing, not least because of the groan-inducing punning names of some of the supporting characters. Music by Paul Sawtell.
