Mission 12 - Railway

The crew of Rosie are tasked with delivering items to a refugee world when they get word from the Fenris Rangers that they need help searching for a refugee ship. On the way to the meeting point of another ship tasked to assist with the search, the crew find them in an awkward situation of swapping bodies with other members of the crew. How did that happen and how do they fix it back to allow them to their jobs?