(The scene opens in a city street, which appears to be wet from rain, jazz music playing as a red car drives into the scene. The driver appears to be a lady wearing purple glasses and a pink bandana. She is later shown to actually been followed by a black blob.)
Black Blob: (laughs maniacally)
(Droopy and Dripple are shown driving a blue rundown car, and the red car drives past it, causing it to spin around until it is pointing at the opposite direction. The red car recedes to meet the two detectives, and they greet the driver.)
Mystery Lady: Follow me. (drives away)
Dripple: What was that about, papa?
Droopy: I think the master detectives has just found his next case, son.
(The detectives drive away. The scene cuts to the same red car again, followed by the same black blob, laughing maniacally. Droopy and Dripple follow them as well. While turning at a curve, they spin around for a while before moving on. The two cars pass a puddle, splashing all over the black blob.)
Black Blob: (cursing) miserable (cursing)
(The chase goes on. At some point, a bridge opens. Cut to Droopy and Dripple turning their car at a curve awkwardly.)
Dripple: Yes papa?
Droopy: Is your seatbelt tight enough?
(The car skids to a halt. The black blob goes underneath the car.)
Dripple: (looks down at seatbelt) Yes, papa. (to audience) My papa really takes good care of me.
(Their car starts to run again, and so is the black blob. A boat rides under the bridge seen earlier, and the red car takes off from the tilted road from opening the bridge, lands onto the flat land, and takes off. Droopy and Dripple do the same, but their car stretches apart as a result of the opening, and takes off like a catapult onto the flat road. The black blob does the same, but he fails and falls into the river. The red car stops, and waits for Droopy and Dripple to arrive, but is stopped by a large bus. When it leaves, the red car is gone.)
Dripple: Looks like we lost her, papa.
Droopy: Yes, and the case too.
(The screen fades to the door of Droopy and Dripple's detective agency, and Droopy and Dripple walk towards the door.)
Dripple: I'll bet we'll never see the mystery lady again.
Droopy: (opens the door) Win some, lose some.
(They open the door to find the mystery lady sitting on their desk.)
Mystery Lady: (glasses reflecting Droopy's face) What kept you?
Dripple: I wish I'd taken the bet.
Droopy: How may we be of service?
Mystery Lady: (walks toward Droopy and whispers in his ear) Can I trust you?
Droopy: (excites himself, and his heart lunges out. He crosses his heart, literally.) Cross my heart.
Mystery Lady: I need your help. I've been followed. The Blue Pigeon is in grave danger. (opens window) Must go now. (jumps out)
Dripple: (looks down window) Boy, is she mysterious or what? (walks away, reads newspaper) Here's a clue. (reading) The Blue Pigeon, priceless gem, on preview at the museum. (to his father) What do we do, papa?
Droopy: Case reopened. Let's rumble.
(They run, and the door slams behind them. Zoom in to lamp to reveal black blob, who had been overhearing their conversation.)
Black Blob: (laughs maniacally) They don't know (continues to laugh)
(Fade to Droopy and Dripple driving their car, as the red car passes through until the driver meets their eyes.)
Mystery Lady: Your lives are in danger! (drives away)
Droopy: (coughs with Dripple, slightly weakly) Yes, from the car exhaust. Let's see. First, it was "Follow me."; then, "Can I trust you?"; now, "Your lives are in danger." What next?
Dripple: How about, "Let's go home."
(As they were driving, the black blob, who was hiding behind the mailbox's shadow, laughs; and reaches for the pothole. He opens it, and Droopy and Dripple fall in. They are now driving through the sewer pipe.)
Dripple: What now, papa?
Droopy: Watch out for alligators.
(A sign says, "To the museum", and Dripple reads it. They follow the sign, and end up launching from the pothole onto the base of the steps to the museum. They walk up the stairs, only to be met by the police chief, with a row of police officers behind him.)
Police Chief: Glad you're on the job, master detective.
Droopy: Always vigilant, chief.
(Fade to museum hallway.)
Chief: We have every type of surveillance equipment in, oh, (cut to monitors) TV monitors, tripwires, (cut to room with laser beams) laser beam detectors, in case anyone is foolish enough to touch the Blue Pigeon.
Dripple: You mean like this? (touches a bit on the gem)
(The door to the room closes, locked; and all the museum doors and windows lock down with bars, a cage encloses on the group, and they get tied up. Alarms wail incessantly.)
Droopy: Well there's one thing we know.
Chief: (angrily) What's that?
Droopy: (to chief) Everything works.
(Fade to Droopy and Dripple walking through museum hallway, bird's eye view. The black blob tries to scare them by going over them.)
Dripple: What are we looking for, pop?
Droopy: Anything that looks suspicious, son.
(They continue to walk, the black blob still following them, until they come to a bare wall, and Dripple starts making a shadow dog.)
Droopy: That's very good, son. (The black blob makes himself into a dinosaur about to chomp the dog) Oh, how did you learn to do that?
Dripple: I'm not doing it.
Black Blob: (roars, then transforms into his normal self and laughs maniacally)
Droopy and Dripple: Shadowman! (runs away)
(Shadowman follows them while walking. He laughs again. Droopy and Dripple hide behind a wall. Droopy is seen making a paper man.)
Dripple: Here he comes!
Droopy: (opens paper man to reveal more rows of paper men) We're ready for it, son.
(Shadowman tiptoes and continues to laugh. He stops at a giant foot, and sees more giant, angry rows of men. He freaks out, and runs away.)
Droopy: He's on the run now, son.
(Cut to the Blue Pigeon. Shadowman tiptoes closely to it and tries to take it, only to be stopped by Droopy and Dripple.)
Droopy: Drop that egg shadow, bub.
Shadowman: (speaks gibberish)
(Droopy runs away, and takes Dripple with him as well; just as the same cage falls again. Pan to Droopy holding his son.)
Droopy: A master detective never makes the same mistake twice. (Cut to Shadowman taking the Blue Pigeon with him.) Stop, in the name of the Ladies of ??? Police Association.
Dripple: (to audience) That terrifies him every time. (Shadowman looks back at the pair and laughs again. He runs away without getting terrified.) Well, almost every time.
Droopy: Come on son. Let's boogie. (walks away)
(Fade to someone's house. Shadowman hides in the fireplace as Droopy and Dripple walk in. They stare at it.)
Dripple: What do you think, papa?
Droopy: Either it's Shadowman, or Santa Claus is a little early this year.
(Shadowman climbs up to the chimney, and laughs. Crickets chirp. Suddenly, he feels something pulling him down. Cut to reveal Droopy and Dripple vacuuming the fireplace.)
Shadowman: Hey! Wait! You can't— (speaks gibberish while he gets transported to the vacuum bag, struggling)
(Fade left to Droopy and Dripple holding the bag. Police chief skids in.)
Chief: Where's my jewel?!
Droopy: It's in the bag. The Blue Pigeon, and the "Poor Pigeon". (throws bag to chief) Bub.
(Fade to Droopy and Dripple driving.)
Dripple: Hey papa, that was good solving.
Droopy: Remember son, hard work and a fat-free diet is what it takes.
(The red car passes them, and it's déjà vu all over again.)
Mystery Lady: Follow me boys! (drives away)
Dripple: Uh oh. What do we do now, pop?
Droopy: Exit. Stay right.
Dripple: Which side is right?
Droopy: On your left, son.
(The car turns into the opposite direction, and they drive away into the night. Fade out to black.)