The Invis­i­ble Front is the gal­va­niz­ing sto­ry of Major Gen­er­al Mark Gra­ham and his wife Car­ol, whose all-Amer­i­can army fam­i­ly was shat­tered by the loss of their two sons, one to sui­cide and one in com­bat. The Gra­hams have devot­ed their lives to fight­ing the mil­i­tary sui­cide epi­dem­ic that is the dark lega­cy of Iraq and Afghanistan and that will rage on long after those wars have come to a close. That means chang­ing the way the mil­i­tary looks at men­tal health, and it means chang­ing the cul­ture of an army that all too often sees men­tal health prob­lems as a sign of weak­ness and shuns those who seek help.