Marvel's Agents of S.H.I.E.L.D.: Mack and Yo-Yo's Relationship Will Be Tested

While the rest of the team struggles with gravity storms on the surface of their broken planet in this week's Marvel's Agents of S.H.I.E.L.D., Mack (Henry Simmons) and Yo-Yo (Natalia Cordova-Buckley) will be fighting the good fight for the humans' freedom back on The Lighthouse.

Even though Mack and Yo-Yo make a formidable team, this particular fight will test them in new ways. Building a rebellion isn't always easy, and it's especially difficult when you and your significant other have very different ideas on how and who to fight.

"There's a lot of tension between us," Simmons says of Mack and Yo-Yo's conflict, "because -- and I think two seasons ago you started seeing it a bit -- Yo-Yo is the kind of person that is quite impulsive, who wants to act rather than plan, and Mack is the exact opposite. I think he wants to plan before he acts out. So that creates tension between the two of them."

That impulsive nature is part of what makes Yo-Yo such a great freedom fighter (and speedster), but it's not the only thing complicating matters in this rebellion. Yo-Yo has some personal baggage she's bringing into this fight, which makes her more motivated than ever to take Kasius (‎Dominic Rains) down.

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"Yo-Yo feels really intense about anyone who is just unkind and evil to people that don't have power," Cordova-Rodriguez says. "She's just very much about justice and protecting the 'little people' -- I put little people in quotations because no people are little. She just has a very strong belief in not putting others down and not stepping on other humans. She's always fighting for others, so I think it just really angers her. That anger takes her all the way back to when we first met her in Colombia. She suffered a loss, she's lost a lot of people because of powerful men like Kasius, and she's just not having it anymore. I think it's just part of her. And it's that radical part of her -- she doesn't plan, she doesn't think, she feels and she just goes. It's a really great quality and then at times it also gets her in trouble a lot, specifically with Mack."

When you factor in Yo-Yo's history with corrupt, powerful men exploiting and abusing the "little people," it becomes way clearer why she'd want to face this fight so head-on. On the other hand, with strong emotions like that motivating her, she might not be able to think twice before rushing into danger.

That danger is exactly what makes Mack so nervous. Just because they don't see eye to eye on this matter, that doesn't mean Mack wouldn't be absolutely crushed if something happened to Yo-Yo.

"I think there's tension because Mack still wants to protect Yo-Yo," Simmons says. "He doesn't want her to get hurt, so therefore there's this protective mode that he goes into... He knows that she has to get involved, but he only wants her to get involved to a certain extent. He doesn't want her on the line actually doing things where her life is in jeopardy, and she wants to go there."

Will Mack's protective instincts keep Yo-Yo out of harm's way? Or will these two end up butting heads too much to win this fight?

Marvel's Agents of S.H.I.E.L.D. airs Fridays at 9/8c on ABC.