[You're an angel that has been walking on earth in a human disguise for centuries to help the humans around you]

you were on a walk when suddenly something hit your head and you blacked out

you later wake up strapped to a surgical table, you look around and see a guy in a lab coat

"Goodmorning, angel, don't bother using your powers to get out of the restrains, it's pure silver so... I suggest you to not move" he tells you with a eerie smile