Hey guys...What season is Castle up to now?

Yes you may think I`m crazy but I stayed up on saturday night and saw that castle was on at 12.10am...It has never been aired apart from at really late at night when they started showing it about two weeks ago. So was wondering what season is it at cuz I`ve heard about it for quite awhile but woz wonderin...and after one episode I`m hooked it very alike my fav show The mentalist:D
The episode I seen was where the teen is found shot dead into a little rowing boat in a park and all his friends are suspected, but It turns out they all bluetoothed videos to each other...does that make sense? Just wondering but I already love the pairing Caskett!