[Hearing her say that was enough to bring Natsu to a full halt from shock. It stole one of her keys. One of her important friends...]

Lucy...Kh

[Without another word he stormed onwards again, a glare of pure determination all over his face. The bastard not only hurt Lucy but stole something so important from her. Oh they were going to pay. They were going to pay with interest and then some]

We'll get it back. Don't you worry.

[And by we he more or less means HE will get it back.]