Phantom track

I built a midi drum track as part of a larger project. For unknown reasons the track disappeared, but it still plays with the other tracks. I did the Hide/Unhide track trick and this track doesn't unhide the mystery track. The only way I can turn the output of this track off is to mute the Output track. It's still there after muting all the visible tracks. Is this a bug...or do I need an exorcist?