Still Holding On (слэш)

"I have built dozens of holes in this plan," Loki hisses. "Find them."
 
When Loki tries to sabotage his own plan, the only reasonable explanation Tony can think of is that he wants to go back to Asgard, and that alone is more than enough reason to keep him on Earth. Tony reluctantly agrees to keep Loki in Stark Tower just long enough for Thor to talk to his father about how to proceed.
His visit ends up lasting much longer.