Jimmy thought for a moment and said, "First, it's known that Tom currently has three mobile numbers. The CIA said Tom died on a mission, and Tom's family couldn't reach him either, so we can only believe what the CIA says, since being an agent is indeed a dangerous job.
If Tom indeed died on a normal mission, but it happened so suddenly that he left no will, the CIA would surely handle his belongings, at least his phones used for external communication.
Why weren't these other two phones handled? If these two phones were secret, and no one else knew about them, it implies that Tom stored these phones somewhere safe before he left. If we could locate these two phones, we might find something Tom left behind."
Besides, normally, even when Tom was on a mission, he would have made arrangements like a will prepared in advance. So, could there be other messages still undiscovered?