Self Preservation

Kaylen either told the angels where Mark would be coming from while hoping that Mark would be killed by their ambush, or Kaylen told someone else about the position even after Mark told her explicitly not to tell another soul about it. 

Either option was bad enough to warrant death as far as Mark was concerned. Mark despised traitors and had no use for someone who was incapable of listening to even the most basic commands. 

Kaylen squeezed her hand against the table and tried her best to keep her heart rate under control as she wondered what Mark was going to do. 

Truthfully, Kaylen felt angry inside her heart! She was so stupid not to have looked into the information that the demon lord sent to her before sending it to the Angels. If she had checked what the demon lord told the other members of the council before going, then she would have figured out that the demon lord was trying to catch her!