Please consider 2-acetyl-1-pyrroline:
http://en.wikipedia.org/wiki/2-Acetyl-1-pyrroline

<img src="https://i.sstatic.net/mlQaI.png" width="86" alt="1-(3,4-dihydro-2H-pyrrol-5-yl)ethan-1-one">

What is the molecular geometry of the nitrogen lone pair?  Is the lone pair oriented in-plane with the ring?  How is this distinct from the orientation carbon-acetyl bond, which should presumably point out-of-plane with the ring?