reestore an external disc
I aim using time machine for backup. I have connected a usb hub and connected a specific external drive to it only to be used as a dive containing a community books that I user. The drive has been corrupted and I reformatted the drive. I wasn't to resort from a backup on a certain date. The backup drive (another external drive that I only use for backups) shows the backup was done on a certain date, but when I go into Time Machine, the disk is greyed out. What is the correct way to recover the files; there is some 400 files.