I've come across an idiom in the book I'm translating. 'll be grateful if you can help. The context is like that: You couldn't expect you pod-people family to get that through. They aren't the sharpest knives in the drawer.
Thx a lot in advance.
"The sharpest knife in the drawer" means "the most intelligent person" (in a group, family, class, etc.)
Sharp is often a synonym for "intelligent.'