Flashbacks reveal Michael and Theo were roommates and best friends. 

Theo was there when Michael and Travis proposed to each other, and the trio celebrated Theo's promotion to captain together.

Travis later tells Michael he has worries about Theo being Michael's captain, but Michael brushes them off.

After Michael dies, Theo tells Travis it was his fault, and Travis yells at Theo to get out of his house.

In the present, Travis and Vic continue to fight about Theo.

Vic reiterates that she and Theo aren't dating, but Travis doesn't want to hear it.

They bicker as they work together on the aid car for the day, treating overdosed victims, and get into a screaming match on the side of the road.

Travis then questions if Vic even cared for Ripley, and Vic pushes back.

Vic accuses Travis of holding onto his anger, and Travis later concedes that Vic is right. 

Travis is scared to let his anger go because it means that Michael is truly gone.

Travis and Vic later make up.

Elsewhere, Marcus fears for Jack's safety whenever Jack goes to work, so Jack and Theo put together a way to show Marcus how safe Jack's job is.