Sam sent the team and Arkiv to the city so that they could investigate. He also let the shadow mice go. Arkiv is mostly concerned about the rest of the players. He communicated with other players the most, every just thinks that he is sociable, but what they don't know is that he has a keen observation towards the behavior, habits and the nature of people.
That is the reason Sam wants to work with him. After all, he doesn't need any sociable people with him, his beasts are a better company than any other creature could give him.
Arkiv's special understanding towards the other players is the reason why Sam made an alliance with him and another reason is that they became a bit closer with time. He is the best person to see if there is any activity of other players nearby.
He could pick up subtle clues and track them back to their estimated locations and hiding spots.
Sam kept Night Ghost with him as they went towards the location that Old Beast told about.
