Tuesday has a personality that shines. I am not kidding when I say it is common for people to pull out their cell phones and take pictures of and with him. Tuesday is that kind of dog. And then, in passing, they notice me, the big man with the tight haircut. There is nothing about me--even the straight, stiff way I carry myself--that signals disabled. Until people notice the cane in my left hand, that is, and the way I lean on it every few steps. Then they realize my stiff walk and straight posture aren't just pride, and that Tuesday isn't just an ordinary dog. He walks directly beside me, for instance, so that my right leg always bisects his body. He nuzzles me when my breathing changes, and he moves immediately between me and the object--a cat, an overeager child, a suspiciously closed door--any time I feel apprehensive. Because beautiful, happy-go-lucky, favorite-of-the-neighborhood Tuesday isn't my pet; he's my service dog." Captain Luis Montalvan returned home from his second tour of duty in Iraq, having survived stab wounds, a traumatic brain injury, and three broken vertebrae. But the pressures of civilian life and his injuries proved too much to bear. Physical disabilities, agoraphobia, and crippling PTSD drove him to the edge of suicide. That's when he met Tuesday - his best friend forever. Tuesday came with his own history of challenges: from the Puppies Behind Bars program, to a home for troubled boys, to the streets of Manhattan, Tuesday blessed many lives on his way to Luis. Until Tuesday unforgettably twines the story of man and dog.