FCPX - hearing audio but no audio clip visible?!

Working on a timeline. Dropped in a small music cue from Browser. Cue doesn't seem to want to move to timeline. Let it go. No clip on timeline. Re-drag music cue to timeline, it works this time. Position it. Dip the level a little bit. Then I'm playing it ... and suddenly there is the SOUND of a second track of the music cue. Loud. But nothing is visible. I delete the cue that did seem to come in properly from the Browser. There is absolutely nothing above or below the timeline that suggests this particular piece of music cue ... but there it is, I can hear it. And can't get rid of it. I rebooted FCPX twice, then rebooted the computer. Still there - a chunk of audio that can't be seen but can be heard.

Anyone ever heard of something like this?