Is there anything in Pendragon publications (I've got a lot of the PDFs from drivethrurpg + Pendragon and GPC) that has a scenario related to a missing nobleman that the PCs must search for and find? This situation has come up in my campaign and I'm drawing a blank on ideas. :-\ Hoping the Pendragon forum can help me out.

Nothing comes to mind off hand, but I would say that there are two or three simple routes you could take.

1. Noble has no heir. Has been kidnapped by relative who stands to inherit. Locate tower where noble is being held someplace "dark and dangerous". Put a few monsters between PCs and Location - and then some knights there to defend the place.

2. Fae too noble because of an insult he did. They must "redeem" him by fulfilling a quest.

3. "Evil Baron" (tm) has kidnapped noble because the baron wants his son to marry the noble's daughter in order to add the noble's lands to his own. See #1 for further ideas.

Malory's Morte d'Arthur has a number of stories about knights/nobles who are being held in dark towers and who are later rescued by "insert famous named RTK here".

Hope that helps you out some.