About a month ago, a fishing boat with four crew from Sokcho crossed into North Korean waters. So far, I think no one is publicly saying why although suggestions of navigation equipment or engine failure have been common. I have not heard anyone mention espionage although it is probably in everyone's sub-conscious.
Last night, they came home. Well, they were returned to South Korean territory -with their boat. I suspect none of the crew have been home nor will be for a few days longer. They may have had some contact - closely monitored - with their family.
For my mother and other foreign visitors, I think the return of the fishermen is connected to the offers of family reunions for Chuseok (An important holiday coming soon); both are related to offering more of a carrot to South Korea. The previous government was very North-friendly but the current one is not (and I approve, for all that's worth). Threats and missile launches haven't brought significant offers of aid so North Korea is trying a friendlier tack.
Anyway, on to some links:
The Korea Times
The Marmot's Hole