External hard drive won't show up on finder (theres more to this) So I plugged in my hard drive, and deleted a file on it, a .nfo file. I forgot I had a file in the trash and so when I ejected the disk, my mac prompted me an alert like "disk is in use" with a force eject button. I force ejected without thinking, because I really didn't think any of my files were in use (I checked the usual places like whether a video file was playing somewhere etc.) When I try to plug it back, I realise it doesn't read or appear on finder. I've restarted my computer and still nothing. Other hard drives work so its definitely an isolated problem. Any ideas? 

Update: I can't do a Disk Utility repair? the option isn't even available
You should be able to see your drive in Disk Utility, even though the data may be corrupted, so you may need to wipe the drive in order to make it usable again.