Either YoYo gets her speed back FAST, or the Agents are stranded in 1983 in the latest S.H.I.E.L.D.

Episode 8 "After, Before"

Still in 1983, the S.H.I.E.L.D. Zephyr’s time-jumping engine is malfunctioning...hiccupping, pushing the ship forward in time in increasingly more frequent and shorter jumps. Simmons calculates that their “skipping stone” jumps will not end well when they run out of momentum. The time-jumping device is now protected by a forcefield that Simmons wasn't aware existed, and the wavelengths are much too fast for a normal human to reach between and disable the device. If only YoYo could get her speed working again…which becomes this episode’s time-sensitive (no pun intended) mission for the Agents of S.H.I.E.L.D.

Fortunately, Daisy knows someone in 1983 who can probably help: her mother Jiaying, who leads the secret sanctuary for Inhumans we have seen in previous seasons. So, YoYo and May head there, beginning a very YoYo-centric episode, where we will learn much more about her than ever, and really get inside her head. Especially when Jiaying determines that’s where her problem seems to be, since there’s nothing physically wrong to keep her powers from returning.

YoYo has to prove she is an Inhuman before they will help her.

It’s too bad Daisy is still recovering from her injuries, and can’t come along and see her mother again, not that her mother would know her, since it's 1983 and she won't be born for at least another decade. As Daisy recovers in a healing chamber, is it my imagination, or is an attentive Agent Sosa falling for her?

The episode’s theme seems to be self-improvement, as nearly every character is healing, recovering lost parts of themselves, or getting an upgrade.

Meanwhile, Simmons has been working on a new LMD body for Coulson. Needing his knowledge, they activate him before his body is completed, creating a moment of intense déjà vu for viewers, who recall how traumatizing it was for Coulson to be awake during his first resurrection, as his brain was being rewired. Thankfully, this time Coulson is much more nonchalant about it, and even makes a joke about it.

May’s recovery continues, as well as her empathic ability, which makes a big evolutionary leap forward this episode, which ironically coincides with some of the old May's personality resurfacing, the grumpy side that doesn’t like being too touchy-feely. The scene where she tries to help YoYo explore her psyche and overcome mental obstacles is the only humorous part of this episode. No fun 1980s references or whacky adventures this week. And the only action is when YoYo and May try an alternative treatment to meditation to excise her trauma.

The old May shows up: "This is my worst nightmare"

Will YoYo get her speed back in time to prevent the destruction of the Zephyr? Or will the crew need to abandon ship and live out their lives in the past?

To find out, tune in to ABC on Wednesdays at 10pm EST, on your DVR, On Demand, or at abc.go.com/shows/marvels-agents-of-shield to watch the exciting final season!