How to recover a replaced folder with files in OS X Yosemite?

Question

Hard disks

Hello.
There was a misfortune - when copying a folder from the HDD to an external hard drive, I replaced the folder, in the hope that the missing files would be added (drag and drop with the Command pressed and entering the account password). And the system replaced it with completely new files. Yosemite, Time Machine is disabled. Help with advice on how to get them back from an external drive - there were 50+ gigabytes of photos in the folder for half a lifetime =(