"With assassins closing in and Wakanda's faith in him shaken, T'Challa goes to visit Storm on the newly terraformed Mars. But this will not be a happy reunion, as T'Challa has ulterior motives for his visit. And back home, Shuri discovers who is behind the attacks on Wakanda's secret agents, a revelation that will change everything…"
1)This isn't a friendly thing
2)And Wakanda doesn't seem to have his back, I doubt this will be him negotiating or getting leverage for Wakanda.
3)He seems to be on the run, maybe wants refugee
3)He has ulterior motives, refugee as a front could be a possibility.