Your Highness! Ludwig is asking for your help.
if by Karl's Plea: He claims that even though you hold Jaims, Childerich is putting pressure on him. He asks you to keep him busy.
OR if by Ludwig's Request: He claims Childerich is making moves against him and he wants you to keep him busy.
Your Highness! Childerich IV has no other option than to deal with you. Good, you bought Ludwig in the south some valuable time.