Question: Why didn't Mace want to tell Stringfellow Hawke where St. John is? Did Dunkirk tell him not to, or was he working with the people who were holding St. John prisoner?
Answer: I don't think it's ever explained why Mac refused to tell Hawke where St. John is.
Chosen answer: Archangel and the Firm provided fuel and armaments. Dom and Hawke would have had to transport them to the lair to refuel and rearm.
Grumpy Scot