Danny Ainge calls up RM (Phoenix gm) and finds out Dragic is going to be traded to the kings once a 3rd team is found to help facilitate the deal.
As much as he doesn't want the Kings to be successful (since he wants to pursue a trade for Cousins), he agrees to help facilitate the trade. He knows some other team like Philly will act as facilitator if he doesn't.
Here's what Ainge should do:
BOS receives: Thompson, Stauskas
SAC receives:Dragic, Bass
PHO receives: Collison, future protected pick (via SAC), future 2nd (via BOS)
The Celtics get Stauskas for taking on Thompson and helping facilitate Dragic to SAC.