Coulson is unaware of a dark secret May is hiding, even as the two grow closer; Aida is determined to find the Darkhold.

Agents Sam and Billy Koenig are hunted down to get at the Darkhold book, and only Phil Coulson and the team can save them before the clock ticks out.

Daisy, Director Mace and the S.H.I.E.L.D. team must find a way to contain an explosive Inhuman. Meanwhile, Coulson and Mack come face-to-face with Radcliffe’s inspiration for Aida.