The hostages in question were the family of Rafael "Big Rocket". Not only did Tristan promise to him to help, Rafael had helped Tristan too much to leave him on his own.
Thanks to Rafael, Tristan had sent his worms and viruses into the Cuatro Angulos network, and had an excellent electronic view of their actions since then.
At the moment, Rafael wasn't even aware that Tristan was doing all this. He was on a music tour, probably also smuggling drugs for Cuatro Angulos as they forced him to. Tristan got the information about his family from hacking and listening to Cuatro Angulos' network.
It was better if he couldn't spill the information to anyone, even by accident.
***
It took several hours to reach the town where Rafael's family lived.
This extraction mission was going to make Tristan and his team a signal on the enemy radars, but if he proceeded with the main operation before doing this, the hostages could be threatened.
