With Tryndall being the first among the group to start talking about the course of action they would take in making sure that they would be able to apprehend Merdus, everyone in the group went ahead and listened to what instructions he gave to the reconnaissance group.
According to what he told the reconnaissance group, one of the assassins would have to head towards the location that Lucas had told the three of them earlier to make sure that Merdus' residence was indeed there, confirming that he was present in the residence as well. Then, if that assassin were to find out that the residence was not there, they would search the immediate area of that location to find out where the residence truly was.