Reliable, stable Hawk takes off, and Vivian is devastated ... Emma finally has her big family, and she and Craig are dealing with the complexities of being new parents, while Hawk and Vivian have become parents of twins, again. When Hawk's personality suddenly changes, Vivian has a mystery to unravel that she will need everyone's help with, or risk losing her husband and the father of her children forever. Dani and JT, thrilled to be entering a new phase of their life, struggle with something nobody should have to deal with, but that veterans often do, leaving them unable to help Vivian, while they try to claw their way back to health and happiness. The Heat gang needs more help than they've ever needed before, even as life appears perfect from the outside.