Resurrection of Phil Coulson

Phil Collison, an agent of S.H.I.E.L.D., was resurrected after the battle of New York and the circumstances surrounding his return were hidden to all but a few.

Background
Loki was taken prisoner and placed aboard the S.H.I.E.L.D. helicarrier. Unknown to all, that was what he had planned.

Resurrection
Nick Fury decided to do all he could to bring back one of his best agents.

Aftermath
S.H.I.E.L.D. told Audrey that Coulson had died, and she cried for days.

The Clairvoyant wanted to know how Collison returned so he could use the same technology for his Centipede soldiers.

Coulson's team found the drug GH.325 and administered it to save Skye's life after she was shot by Ian Quinn.