A trigger has a way of hitting you when you least expect it. 

You're living your life and suddenly something happens that unleashes a memory you hadn't thought about in years. Or a feeling you've tried to avoid. 

9-1-1 Season 3 Episode 4 explored triggers in a very effective way. And put one of the first responders into a very dangerous situation. 

For Maddie, the crash of a plate on the ground set off a feeling of absolute terror and despair, as she was immediately reminded of her ex-husband and the abuse she endured. 

Previous flashbacks showed that a simple accident like the dropping of a dish was a terrifying moment for Maddie. And she was so rattled that she literally ran from Chimney. 

When she got the call from Tara and heard the silence and then the booming voice of the man looking to keep her quiet, she knew exactly what was happening. 

Related: 9-1-1 Season 3 Episode 2 Review - Sink or Swim

She had been there before many times, and from the second that call ended she was determined to do something. 

But in attempting to do the right thing, she's put herself in a precarious situation. 

Sitting outside the couple's home, and tracking Tara to her place of employment means that she has officially crossed many lines. Not to mention the fact that she almost ran Vincent over. 

Maddie's heart is always in the right place, but what is her next move?

This is a storyline that is sure to play out over time. And the show is wise to show the reality of trauma. 

Maddie had a traumatic marriage, and she went through an extremely traumatic experience that resulted in Doug's death. She may never get over those events. 

Chimney can sense her struggling, but Maddie isn't quite ready to let him all the way in. Hopefully, that changes over time, and she allows herself to be vulnerable. 

Speaking of struggling, Buck continued to be a walking ball of emotions. 

It was great to see him back at the firehouse and back among his family, but the longer he stays away from his passion, the angrier he's becoming. 

You can't blame Buck for being frustrated. With everything he's been through, he doesn't want to waste another minute pushing paper and not using his skills to help people in need. 

But on the flipside, Bobby isn't wrong to be concerned about Buck's mental health. Two major life events happened to Buck in a very short amount of time, and Buck never dealt with his surgery properly.

It's also safe to assume he hasn't dealt with his feelings in regards to the tsunami either. 

Related: 9-1-1 Season 3 Episode 3 Review - The Searchers

Buck pushed himself physically to rehab and get physically fit for the demands that being a firefighter requires, but what about his mind? 

Pitting Buck against Bobby and the 118 is sad on many levels, and while it's a very fascinating twist in their dynamic, I hope there isn't irreparable damage done to one of the best relationships on the show. 

And if Buck does indeed win, what does that do to Bobby going forward? This lawsuit is going to have very real repercussions down the line. 

The major case of the week involved a mother and two sons literally hanging on for their lives when their car careened down a cliff. 

Since Lena appears to be sticking around for a while, it was good to see her in action and see how she fits within the team. 

She and Chimney worked well together, and the brief scene between Chimney and the young boy trapped in the car was powerful and touching. 

Camden: Is she dead?
Chimney: No, Camden. She's not dead.
Camden: Good. Jesse's only nine. He's too young to not have a mom

• Permalink: Good. Jesse's only nine. He's too young to not have a mom

Camden's desire to protect his brother and potentially absorb that pain triggered a genuine emotion in Chimney. And the brother's subsequent reconciliation triggered something in Hen. 

Hen seemed very much on the fence about expanding her family, when the reality of the future started to creep into her mind. 

Denny and the new baby would have a pretty decent age gap, and as much of an adjustment as it would be for Hen and Karen to have a newborn, it would be very challenging for Denny as well. 

Hen and Karen's beautiful conversation in bed highlights why they are such great parents and why they will be amazing parents to their future child. 

They're in a beautiful space that allows them to communicate effectively, and they feel truly supported by one another. 

Things haven't always been smooth sailing for them, but they came out of the rocky times stronger than ever. 

Lena: Look, everyone deals with trauma differently. I don't know your kid but, I know what worked for me. It was when my mom let me know how she was feeling. That she was sad and that is was okay. However we felt, we were in it together. No matter what.
Eddie: Sounds like good advice.
Lena: She's a good mom.

• Permalink: She's a good mom.

Eddie was growing increasingly worried about Christopher, and he did the right thing by taking him somewhere to get him to talk because he wasn't talking to him. 

Related: Enjoy UNLIMITED access to thousands of Movies & TV shows with Amazon Prime Videos

But Lena's advice was perfect, and it allowed Eddie to open up to Christopher. 

The death of his mother, quickly followed by the tsunami, has to have Christopher scared and sad. And he knows that if he's feeling that way, his father must be feeling that way. 

Christopher is a gem and very wise beyond his years. He wants to protect his father, and Eddie wants to protect him. 

And this show needs to protect them both at all costs!

Loose Ends

• Hopefully, Eddie and Lena just stay pals because the romantic chemistry is not there. 

• Domesticated Athena and Bobby are the best, but Athena was a little messy inviting Buck over without saying anything.

• Did anyone else just learn about margarita burns during this episode? Or is this common knowledge?

We've gone from tsunami to internal chaos with Buck suing the city, and things are heating up. 

Drop me a line in the comments so we can discuss everything. 

If Buck can't talk to anyone involved with the 118, can he not talk to Maddie?

Do you agree with Bobby's assessment about Buck?

Has Maddie gotten in over her head? 

Please make sure you watch 9-1-1 online right now if you're behind. Don't miss a minute of the action!

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Whitney Evans is a senior staff writer for TV Fanatic. She is a lover of all things TV. Follow her on X.