Clicking is bad. Try to take it out of the enclosure (if it's not in warranty) connect it directly to the PC see if it can read it. If not, there are a few tricks to try. Freeze the drive overnight, plug it into a system right away the next day (meaning don't wait for it to warm up), see if it sees the drive. Copy the files out it it immediately, don't mess around with it as this may only fix it for a while.
You can also do a short drop, very flat, onto a desk.
Both of these are very low chance of working, but better than nothing or spending a few hundred + to have the drive fixed in a repair shop.