Plot summary
Daisy coerces Simmons to help track the Watchdogs' actions, discovering that the group hacked the Inhuman list using an Inhuman's monitoring device. Coulson visits Morrow in prison, but gets no answers. Reyes arrives to talk to Morrow and Mack recognizes him as the Ghost Rider; they capture Reyes and earn his trust. He visits Morrow and learns that the Momentum explosion was caused by a group of scientists studying the Darkhold, a mysterious book. Only Lucy's husband Joseph, whom Morrow put in a coma while trying to stop the experiments, survived.
Daisy and Simmons find the next Inhuman on the list, J. T. James, and destroy his monitor, but he betrays them—he hates being an Inhuman and is aiding the Watchdogs. Coulson and Mack, alerted by the monitor's destruction, arrive to save Daisy and Simmons. The Ghost Rider defeats James. They then get May to help find the Darkhold. Aida supervises May's recovery as a Turing test by Radcliffe, but Simmons deduces her true nature while being set to take a lie-detection test for Mace.
Credits
Adapted from Wikipedia contributors, Agents of S.H.I.E.L.D. season 4. HTML formatting and reference markers removed.