The shadow mice gave some information regarding the players as well as the two large groups that arrived in the city.
The first information is that the players are indeed planning something and Kumar who is in company with some unknown group is trying to do something at the Thunder Phoenix valley.
As for Dayus, the information is not much valuable, because Dayus refused to talk about the plan and he even directly said to the young master he is accompanying that some is listening their conversation.
Even though young master repeatedly assured that there is no one, he still insisted that someone is listening and if that person listens to their plan, they would be back to square one.
They only communicated through writing and that too in a cipher.
Sam suspected that Dayus might be implying about him, but there is no way to know at the moment.