Invasion of Heaven

Following the recent death of the Nephilim Jack, his soul ascended to Heaven but this was sensed by the shadow who broke through and invaded Heaven to drag his soul to The Empty.

Prelude
Suffering from an unknown illness after his grace was stolen, Jack slowly became more weakened and coughed up blood and hid this from everyone. After a case, Jack's condition worsen and he collapsed while coughing up more blood, forcing Dean Winchester to tend to him.

Rowena is contacted and she determines that because Jack's grace is what holds his human and angel halves in balance, it is coming into conflict with each other, since his grace has been diminished causing his body to shut down progressively. Rowena determines the only way to revert that is for the Nephilim to recharge their grace. Later on, they return to the bunker after Castiel met a Shaman who possessed a vial of Gabriel's grace, which they intend to use to recharge Jack's to hasten his recovery. However, Jack's body rejects it and his condition worsens and it is determined he is dying.

Jack soon succumbs and dies with his soul ascending to Heaven.

Aftermath
Afterwards, Castiel told a protesting Jack that he was r

Trivia

 * As of this battle, all of Team Free Will have died and been resurrected.
 * Castiel's sacrifice for Jack is similar to Mary Winchester defending her sons from the reaper Billie.