After Yi Ku left, Phantom King was still not completely at ease. He took out his jade talisman again and concentrated. He then found out that another Phantom Race disciple was in the city. However, this person took a full two hours before he came as he was on duty.
Not only did this not arouse any of the trio's suspicions, but it also put them at ease. After all, these clansmen were from the Phantom Race' branch lineages only. If they immediately dropped everything and came when the Phantom King summoned them, that would be fishy.
This Phantom Race clansman's story more or less matched what Yi Ku had said. Although he didn't know the specifics, he was certain that something had happened to Jiang Yi.