As explained this week by David Boreanaz himself, viewers will be in for a different Seeley Booth than usual when Bones returns in September.
That's what happens when you undergo brain surgery.
In one of Fox's first promos for season five of the show, we get a glimpse of the changed, slower - alberit still hilarious - character, as his interactions with Brennan are certainly a bit off.
See for yourself:
[video url="http://www.tvfanatic.com/videos/bones-season-five-promo/" title="Bones Season Five Promo"] [/video]