This boy is Death's own Child...
Of course, he was expecting them.
Chiron had immediately suspected when Elder Ellen had said that Lily was going to stay with him. It was at this time that he knew that something was wrong.
Secondly, it must have not been an ordinary matter for it to have disturbed Elder Ellen.
Although Chiron was not aware that Assassins came for his life from another clan, he was roughly aware of the strength of the enemy.
The reason for this was because of the strength of the guard assigned to him.
Lily was of the first stage of the Stone rank.
Chiron knew that Elder Ellen would not assign someone that was not capable to take care of him.
This led him to believe that there were people after his life and since Lily was of the first stone rank, then it meant that his assaulters were of the wood rank.
To make matters worse, the entire clan was aware that Chiron had woken up from his coma. After all, he had ridden along side Elder Ellen on a cored beast earlier in the day.