So the Chronicoms take over the Lighthouse to destroy SHIELD and prevent them from stopping their plans to make Earth their new home.
Sarge, whose is revealed to be a clone body of Coulson made by the powers of the Monoliths and possessed by a dimensional alien named Pachakutiq, is killed by the Heroes to prevent him and his partner Izel from bringing their race to their dimension.
And the season ends with the survivors travelling back in time to 1930s New York so they can stop the Chronicoms from infiltrating SHIELD in it's early days and now made a LMD Chronicom hybrid of Coulson to help them.