So, I need to speak with a certain Northumbrian lord...

In order for the story to progress I need to speak with a northumbrian lord. Problem is, he got captured in battle just a day before I got to him.

What do I do now? Suggestions?

I have only 30 men, so freeing him by capturing the town he's in is out of question.

Can I free him with a raid without capturing the actual town if I don't have the quest to free him given by his relatives?

Also, when I ask other lords about his location, they only tell me he has been captured, they don't know where he's being held. Is there any way to find out?

Please, tell me I don't have to wait for him to be released That would suck so much since I'm kind of rushing the storyline.

You can do a prison break even without the mission active just by talking to the prison guard and going through the usual dialogue choices.

Or you can wait attacking enemies positions, learn to read in a monastery, visit salt mines, being viking...