After a couple of shaky weeks, Agents of S.H.I.E.L.D. is back on track with One Door Closes.
Taking a page out of the Arrow playbook, the episode went with twin timelines, the flashback thread (primarily an excuse to see Lucy Lawless kick ass and take names) laying the groundwork for how the 'real' S.H.I.E.L.D. arose out of the chaos of the rise of Hydra in Captain America: The Winter Soldier.
Meanwhile, back in the present, Coulson and May had figured Mack and Bobbi were working for someone else (they assumed Hydra) and there's plenty of twists, turns, bluffs and double-bluffs before Coulson eventually comes face-to-face with Robert Gonzales (Edward James Olmos) to argue over which organisation is the 'real' S.H.I.E.L.D.
It soon becomes clear, Gonzales' S.H.I.E.L.D.is also interested in getting its hands on Skye.
While this is going on, Skye is hiding out at The Retreat (turns out it was designed by Bruce Banner) when she is surprised by a visit from the eyeless teleporter, whose name is Gordon (Jamie Harris).
He invites her to join more of her kind, transformed by the mists, who will not only encourage her to embrace her powers but guide her in controlling them.
Having delivered his invitation, and emphasised how S.H.I.E.L.D. is clearly frightened by Skye's new powers, he leaves - saying when she has made up her mind, he will know.
One Door Closes started unsteadily, with the prospect of another protracted S.H.I.E.L.D. civil war, but eventually this developed into an interesting situation where there are essentially three sides in this drama (Coulson's S.H.I.E.L.D, Gonzales' S.H.I.E.L.D. and 'the Inhumans') - all of whom could be good considered the 'good guys' from a certain point of view.
A point worth mentioning - because this episode demonstrated it perfectly - is how strong all the female characters are in this show. Even Simmons, not a physical fighter, takes out a more powerful opponent using her brains, while May, Bobbi, Hartley et al are doing what they do so well.