They must investigate to find out more about the caper, and then act to prevent it. The initial tip-off was a red herring meant to distract the PCs from the actual caper. The PCs must find a dingus. Often an old dingus, a mysterious dingus, and a powerful dingus. The PCs must learn more about it to track it down, and then deal with taking it from wherever it is.
Somebody already owns it.
The dingus is information, or an idea, or a substance, not a specific dingus. Recent Ruins A town, castle, starship, outpost, or other civilized construct is lying in ruins. Very recently, it was just dandy. The PCs must enter the ruins, explore them, and find out what happened. The inhabitants destroyed themselves.